Furthermore, sialylated Lewis a and Lewis y were related with apoptosis; in this sense, Rapoport and Le Pendu found in colon carcinoma cell lines such as HT29 in which apoptosis was induced by UV irradiation, TNFα and anti-Fas, a major decrease of this antigen as well as Lewis x [31]. The gene discussed is FAS; the disease is colon carcinoma.