EP0031 was reported to have high selectivity for RET kinase compared to VEGFR2, greater potency than first-generation SRIs against common RET fusions and acquired on-target resistant mutations, including V804 gatekeeper and RET G810 solvent-front mutations, greater antitumor activity than first-generation SRIs in Ba/F3, a KIF5B-RET-G810R expressing cell line, and increased brain exposure and a higher brain/plasma ratio compared to first-generation SRIs in a mouse orthotopic brain tumor model, which correlated with improved survival. The gene discussed is RET; the disease is brain neoplasm.