NTRK1 and neoplasm: Consistent with the above findings, sunitinib (SU11248) maleate, a multitargeted receptor tyrosine kinase (RTK) inhibitor blocking VEGFRs, PDGFRs and stem-cell factor receptor (aka c-kit, expressed by more than 90% pNETs), displayed remarkable anti-tumor activity in RIP-Tag2 mice by disrupting angiogenesis and pericyte coverage of tumor vasculature [187,195].