Similar to the HaCaT cells, HPV-negative HNSCC cell lines (Figure 5A, Supplementary Table S2) without alterations in the EGFR network (UMSCC1, personal communication with the the Carey and Brenner Labs, publication in process; SCC25, Dataset 1 and [30]) or EGFR amplification (SQ20B, Dataset 2) have lower cell survival with cetuximab treatment than cells with PIK3CA mutation (SCC61, [31]). This evidence concerns the gene PIK3CA and head and neck squamous cell carcinoma.