SDHB and gastrointestinal stromal tumor: In particular, given the known overexpression of IGF1R of SDH-deficient GISTs, the oral IGF-1R TKI linsitinib has been tested in a phase II study on adult and pediatric patients with wild type GIST, including 15 SDH-deficient GIST, showing a clinical benefit rate (CBR) and progression-free survival (PFS) at 9 months of 40% and 52%, respectively, suggesting a potential benefit of linsitinib in this patient population, though no objective responses were revealed [49].