Two cases diagnosed as HG-ESS were reclassified as UUS, and three cases diagnosed as UUS were reclassified either as HG-ESS (n = 1), NTRK fusion-positive uterine sarcomas (n = 1) or SMARCA4-deficient uterine sarcoma (n = 1). This evidence concerns the gene SMARCA4 and uterine corpus sarcoma.