2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/49535We review the status of a class of gauge unified models based on SO(10) group and discuss the main phenomenological implications of these models in particular for neutrino masses.10 pages, Talk given by F. Buccella at the `Meeting in honour of Samoil Bilenky', Torino 1999High Energy Physics - Phenomenologytext