EGFR and cancer: The selective and specific interaction of the CaRA binder with the endogenous receptor was assessed using human cancer cell lines with various expression levels of EGFR; including A-431 cells (high expression), MDA-MB-468, SK-BR3, SK-OV-3, NCI-H292, and BxPC-3 cells (intermediate expression), MCF-7 and Ramos cells (low or no detected EGFR-expression) (36, 37).