2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/146458The purpose of this shord paper is to make the link between the fundamental work of Atiyah, Bott and Shapiro (MR0167985/29/5250) and twisted K-theory (MR0282363/43/8075). This link was implicit for a long time in the literature (for the description of the real K-theory of spheres as an example) but was not explicitly defined before.5 pages,se also http://www.institut.math.jussieu.fr/~karoubi . To be published in the Proceedings of the International Conference on Clifford algebras (ICCA7)K-Theory and HomologyHigh Energy Physics - TheoryAlgebraic Topology19K99text