In addition to HNSCC, RAC1-A159V hotspot mutation has also been identified in endometrioid carcinoma (TCGA-BG-A0MG-01, GENIE-MSK-P-0044987-T01-IM6, and GENIE-MSK-P-0067212-T01-IM7). This evidence concerns the gene RAC1 and endometrioid adenocarcinoma.