M. Carmo-Fonseca has authored more than 150 original research articles, review articles and book chapters with a total of approximately 10 thousand citations (h index 54). Her lab is known for studies on RNA splicing using a combination of cutting-edge cell imaging and genome-wide approaches. The vision of her research group is to understand how RNA molecules, with their ability to both encode information and exert catalytic activities, contribute to the regulation of gene expression and how this knowledge can be translated into novel disease biomarkers and therapies. For the past 10 years, Carmo-Fonseca has implemented methodologies that allow tracking single RNA molecules in time and space inside the nucleus of living cells. She did a sabbatical hands-on training at Harvard Medical School, in Tom Kirchhausen's lab, where she developed a strategy that permits direct measurements of intron dynamics in single pre-mRNA molecules in live cells. This approach revealed that splicing can occur within a few seconds after transcription. To further investigate the timing of premRNA splicing relative to the position of RNA polymerase II (Pol II), Carmo-Fonseca started a collaboration with Nick Proudfoot at the University of Oxford, who had developed a novel strategy for Native Elongation Transcript sequencing (NET-seq). Together they unraveled unanticipated dynamic links between Pol II and the spliceosome. Drawing on her previous work indicating that reciprocal interconnectivity between the different steps required for gene activation plays a critical role ensuring efficiency and fidelity of gene expression, Carmo-Fonseca became interested in understanding how defects in gene expression regulation contribute to disease phenotypes and could be targeted for treatment.