At a concentration of 10 nM, ALW-II-41-27, XMD15-44 and HG-6-63-01 inhibited RET kinase and signaling in human thyroid cancer cell lines carrying oncogenic RET alleles; they also inhibited proliferation of cancer....Inhibition of RET/C634R and RET/M918T phosphorylation and downstream signaling by ALW-II-41-27, XMD15-44 and HG-6-63-01.