The late eighties and early nineties seen research interest grow in this area, as multiple labs studied the PDGF-R and in particular the Insulin-like growth factor-1 receptor (IGF-1R) systems in in vitro models of human malignancies, starting with breast cancer (3, 4) and then extending to lung (5), prostate (6), bladder (7), and others (8–10). Here, IGF1R is linked to breast cancer.