RAC1 and head and neck squamous cell carcinoma: Our results also showed that RAC1 gene expression was higher in breast invasive carcinoma, cholangiocarcinoma, head and neck squamous cell carcinoma, kidney renal clear cell and papillary cell carcinoma, liver hepatocellular carcinoma, lung squamous cell carcinoma, and stomach adenocarcinoma, as compared to corresponding adjacent normal tissues.