Postdoctoral Researchers

Samira Hozeifi

I have been a postdoctoral researcher in Dr. John LaCava’s lab at the European Research Institute for Biology of Aging (ERIBA) since 2021. My research is focused on LINE-1 interactomics. I obtained my PhD (2014) in cellular and molecular biology, genetics, and virology from Charles University in Prague, under the supervision of Dr. David Stanek, where I developed a keen interest in RNA biology, investigating the role of epigenetics in alternative splicing. During my masters, I learned a lot about human genetics and DNA repair pathways under the supervision of Dr. Maryam Neishabury in Tehran, Iran. My long-term research interest is to understand how RNAs and RNPs are involved in the development and progression of human diseases such as cancer and Alzheimer’s disease and ultimately identify novel targets for treatments. I am fascinated by and thoroughly enjoy learning about our tiny molecular world.

Mathias I. Nielsen

I have a background in glycobiology and glycoproteomics and I earned my PhD at the Copenhagen Center for Glycomics at the University of Copenhagen under the supervision of Prof. Hans Wandall. I joined John’s team at Rockefeller University as a postdoctoral associate in January 2023, and in my research I will use different applications of mass spectrometry to study the fundemental biology of LINE-1 proteins and their involvement in various diseases.

PhD Students

Shaoshuai Xie

I started my PhD in Shandong University in 2018, then I joined John’s group as a Sandwhich PhD student 🥪🎓 in 2020. I use mass spectromerty to characterize glycosaminiglycans (heparin/heparan sulfate) and to study the effects mono-O-mannosylations on E-cadherin protein interactions.

Omar Bringas

I got my Master’s degree in Mexico and then I joined John’s groups to do my PhD. I am interested in RNA biology and the interactions between proteins and other macromolecules. I am currently studying the interactions between IGF2 binding proteins and LINE-1 retrotransposons. I am also interested in mass spectrometry and data analysis.


Leila Saba

I earned a Bachelor of Arts in Anthropology from the University of Central Florida, and a Bachelor of Science in Biology from The City College of New York (CCNY, CUNY). Currently, I manage the LaCava Laboratory of Macromolecules and Interactomes in Groningen, NL. I moved from NYC to Groningen with John in 2019. John hired me in 2015 to work as his lab technician in NYC, but I simultaneously served as lab manager in the Rout Lab of Cellular and Structural Biology at The Rockefeller University. Before I began my research career, I worked for over a decade in various executive support and financial analyst roles. I am eternally grateful to John for rescuing me from cubicle life, which was slowly draining my will to live. In combination with my administrative functions, I am also a Research Technician, and have extensive experience with many of John’s experimental protocols. I have particular interest in LINE-1 expression in cancers, and I love immunology in general. Doomscrolling COVID-19 research updates is a fun hobby of mine. Last but not least, Wu-Tang Clan Ain’t Nuthing ta Fuck Wit.

Hua Jiang

I earned an MS degree in Biology from Queens College of The City University of New York (CUNY). I joined the Laboratory of Cellular and Structural Biology at The Rockefeller University in 2006. Since that time, I have been a project coordinator for the National Center for Dynamic Interactome Research. I started working with John in 2008, when he was a recently-joined post-doctoral associate in the same lab, and we have continued working together ever since. In my capacity on John’s team, I am a Research Specialist working on the biochemical characterization of L1 ribonucleoproteins.

Sylvia van Beem

I joined the LaCava group as an intern in the beginning of 2022. After finishing my project I got the opportunity to continue working in the laboratory. So, while finishing my Master of Biomedical Sciences I work in the Macromolecules and Interactomes laboratory as a part-time technician.


Apostolis Mourtzinos

I earned my bachelor’s degree in Biology from the University of Sheffield, United Kingdom. In 2020, I joined the Laboratory of Macromolecules and Interactomes in Groningen, NL as a lab technician. A year later I got enrolled in a 2-year Master’s program in Molecular Medicine and Innovative Treatment at the University of Groningen, which I started in parallel with my position as a lab technician at the LaCava Lab. Now I am on my Master’s internship on John’s team at The Rockefeller University, researching the contribution of LINE-1 retrotransposons in neurodegenerative diseases. My scientific interests focus on understanding the underlying mechanisms of various diseases through investigating macromolecular interactions.

Marko Radovic

I obtained my Bachelor’s degree in Molecular Biology and Physiology at the University of Belgrade, after which I started my Master’s in Molecular Medicine and Innovative Treatment at the University of Groningen. During the second year of my Master’s studies, I joined the LaCava group as part of my final Internship in the Laboratory of Cellular and Structural Biology at The Rockefeller University where I am working on a project connecting LINE-1 retrotransposons with Alzheimer’s Disease.