To explore whether STAT1 and IRF9 participate in the FAT1-mediated phenotypic transition of HNSCC, we compared eight treatment groups: the empty carrier group, the Lv-STAT1 group (STAT1 overexpression), the Lv-IRF9 group (IRF9 overexpression), the Lv-STAT1+Lv-IRF9 group (STAT1 was cotransfected with IRF9), the Si FAT1 group (siRNA was used to interfere with the expression of FAT1), the Lv-STAT1 and Si FAT1 group, the Lv-IRF9 and Si FAT1 group, and the Lv-STAT1+Lv-IRF9 and Si FAT1 group. Here, IRF9 is linked to head and neck squamous cell carcinoma.