Maria Filomena Caeiro has been consistently involved in the identification and phylogenetic analysis of a diversity of organisms, besides eukaryotic viruses. Her participation in projects involving organisms with biotechnological potential and/or environmental impact (marine fungi, microalgae, and arbuscular mycorrhizal fungi) allowed the application and enhancement of her expertise as a molecular biologist, in close collaboration with national and international institutions and researchers. As a virologist, she is engaged in the evaluation of the antiviral potential of plant extracts, in the isolation and identification of new viruses, and in collaboration with Faculdade de Medicina da Universidade de Lisboa and Empresa Portuguesa das Águas Livras (EPAL), she supervised a Ph.D. thesis in Environmental Health, aiming the monitoring of enteric viruses (genomic RNA and infectious particles) in water matrices for human consumption or reuse.