The FAT1 mutant was found to inactivate the Hippo regulatory complex, which leads to activation of YAP1 in HNSCC as reported by Martin et al. They also indicated that the FAT1 gene alteration rate was as high as 29.8% in HNSCC, which is the highest among solid tumors [8]. Here, YAP1 is linked to head and neck squamous cell carcinoma.