In contrast to the D842V mutation, the V561D mutation in PDGFRA may still exhibit sensitivity to specific tyrosine kinase inhibitors (TKIs).140,141 Patients with this mutation may exhibit therapeutic responses, as they could potentially respond well to TKI treatment.142 However, apart from GIST, the occurrence of activating c-KIT and PDGFR mutations in other types of human malignancies is extremely uncommon. The gene discussed is PDGFRB; the disease is gastrointestinal stromal tumor.