PIK3CA and head and neck squamous cell carcinoma: We further established primary murine HNSCC cell lines from two individual PIK3CA‐tumors (hereafter referred to as CU110‐1 and CU110‐2) and two individual control‐tumors (hereafter referred to as CUCON‐1 and CUCON‐2) (Du et al., 2016) to facilitate studying of the molecular mechanisms underlying the PIK3CA‐driven EMT and CSC characteristics.