Titrating cetuximab in cultures of A431 cells (EGFR+++, RASwt), SW480 cells (EGFR+, RASmut) and COLO320 cells (EGFR-, RASwt) demonstrated that cetuximab alone induced cytotoxicity only in EGFR+ RASwt tumor cells (Fig 2A and S1C and S1D Fig). Here, EGFR is linked to neoplasm.