SKAP1 and endometriosis: SNP variation in the SKAP1 region is associated with ovarian cancer, subtypes of which are clearly linked epidemiologically and genetically to endometriosis 25, 45 and to endometrial cancer 46, although rs2278868 is in extremely low LD with the top ovarian cancer SNP rs9303542 (r2 = 0.034) 33.