We should carefully consider the long-term use of TKIs in younger patients and patients who need transplantation.21 In addition, given the indolent state of tumor progression of the proband’s father after the failure of first-line imatinib treatment, it is speculated that GIST with germline KIT exon 11 mutation may have a relatively inert biological behavior compared with sporadic cases. Here, KIT is linked to neoplasm.