PTPN11 and head and neck squamous cell carcinoma: To confirm the therapeutic benefit of blocking both these pathways across HNSCC cell lines, we treated SHP2 inhibitor–sensitive JHU-022 and SCC-9 cells and SHP2 inhibitor–resistant BICR22 cells with the PI3K alpha inhibitor, alpelisib (40), and the MEK inhibitor, trametinib (41).