The most common target genes that harbor MSI in endometrial cancer include TP53, FBXW7, CTNNB1, ARID1A, PIK13CA, PIK3RI, PTEN, RPL22, PTEN, KRAS, ATR, CHK1, CDC5, Caspase 5, BAX gene, and JAK1 mutations. The gene discussed is PTEN; the disease is endometrial cancer.