An increase in the prevalence of endometriosis correlated with an increase in the content of ACTN1: in the group with adenomyosis (group 3) the content of protein and mRNA increased by 89% and 87% (p < 0.05), respectively, while in the group with genital endometriosis (group 4), there were increases of 91% and 86% (p < 0.05). This evidence concerns the gene ACTN1 and adenomyosis.