ESR1 and endometriosis: For example, Kitawaki et al. examined the distribution of PVUII genotypes (PP, Pp and pp) in ESR1 using DNA from blood samples (203 women, 109 with a diagnosis of endometriosis) reaching the conclusion that the Pp/pp variants were higher in women with endometriosis, fibroids or adenomyosis (Kitawaki et al. 2001).