Among the three Ras genes (H-, K-, and N-ras), Hras is commonly mutated in tumors originated from stratified epithelial tissues including squamous cell carcinoma in the skin, head, and neck cancer as well as bladder cancer (Bos, 1989; Agrawal et al., 2011; Stransky et al., 2011). Here, HRAS is linked to squamous cell carcinoma.