EGFR and oral cavity squamous cell carcinoma: Yamada and coworkers [39] reported that in oral squamous cell carcinoma, a prevalent malignant tumor of the head and the neck, activation of EGFR induces via ERK and p30 MAPK PTHrP expression, which, in turn, activates ERK and Akt signalling via PTH1R in a paracrine/autocrine manner, leading to a promotion of tumor malignancy.