The rationale for selecting MCF7, RH-30, DU 145, and ME-180 as representative cell lines to study the potential activity of hR1 and Hex-hR1 in affecting cancer cell proliferation was based on the knowledge that they all express high levels of IGF-1R, as assessed by hR1, and their responses to other anti-IGF-1R antibodies, for example, MCF7 and DU 145 to EM164 [52], and RH-30 to h7C10 [51], were described in the literature. Here, IGF1R is linked to cancer.