Furthermore, afatinib induced tumor regression in a broad spectrum of xenograft models carrying epidermoid carcinoma A431 with wild-type EGFR, gastric cancer NCI-N87 with HER2 over-expression, lung cancer NCI-H1975 with L858R-T790M mutant EGFR, and adenosquamous lung tumor with HER2YVMA mutation, with superior activity over erlotinib (99, 101). Here, ERBB2 is linked to squamous cell carcinoma.