2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/144385Our knowledge of the nucleon spin structure has greatly improved over the last twenty years or so, but still many fundamental questions remain unsolved. I will try to review some of the puzzling aspects of the structure of the nucleon spin, in particular, what is known, what remains to be discovered and the prospects for the near future. I will also focus on some current activities in QCD spin physics.10 Pages, 7 Figures, Invited Lecture at the Workshop DUBNA-SPIN 07, Dubna, Russia, Sept. 02-09, 2007High Energy Physics - Phenomenologytext