IGF1 and neoplasm: A-928605 (Figure 2A) is an optimized pyrazolopyrimidine that has previously been reported to have an IGF1R in vitro enzymatic IC50 of 37 nM as well as an IC50 value of 90 nM for inhibition of cellular IGF1R phosphorylation induced by IGF1 in A431 tumor cells [20].