RET and neoplasm: In contrast, tumor tissues from selpercatinib-treated mice had greatly reduced levels of these activated kinases (Fig. 1g, k, Supplementary Fig. 4), indicating that KIF5B-RET(L730I) and KIF5B-RET(L730V) kinases were inhibited by selpercatinib, but not by pralsetinib, in the xenograft tumors.