NTRK1 and gastrointestinal stromal tumor: Recently, several molecular alterations, including the PIK3CA mutation, neurotrophic tyrosine receptor kinase (NTRK) fusions (ETV6-NTRK3 and LMNA-NTRK1), FGFR1 gene fusions (FGFR1-HOOK3 and FGFR1-TACC), BRAF gene fusions (BRAF-AGAP3 and BRAF-MKRN1) and ALK gene fusion (CDC42BPB-ALK), have been reported in ‘quadruple WT’ GIST [12,13,14,15,16,17,18].