MUTYH and mutyh-associated polyposis: To investigate how MUTYH affects 6-TG/UVA resistance in Mutyh−/− MEFs, we examined the responses of a series of Mutyh-null cell lines expressing variant forms of MUTYH. The p.Y179C, p.R185W and p.G396D missense variants and the p.E480del in-frame deletion were all identified in MAP patients [16].