In addition, loss of heterozygosity at loci containing the tumour suppressor genes, tumour protein 53 (TP53), retinoblastoma 1 (RB1), phosphatase and tensin homolog (PTEN) and cyclin-dependent kinase inhibitor protein (CDKN2A), in uterine leiomyosarcoma confers chemotherapy resistance [6, 7]. This evidence concerns the gene RB1 and leiomyosarcoma.