To confirm the accuracy of RNA‐Seq, six genes including up‐regulated (CEBPB, SERPINE1), down‐regulated (S100A1, CKS1B) and unchanged (SPIN2B, TCTN1) between endometrium from women with adenomyosis and controls were selected for further validation in additional set of clinical samples. The gene discussed is S100A1; the disease is adenomyosis.