PDGFRA and gastrointestinal stromal tumor: In particular, in a cohort of 38 primary, untreated GIST patients, including five cases of PDGFRA-mutant GIST (two D842V mutant) and in a larger cohort of 77 GIST patients, including 15 cases of PDGFRA-mutant GIST (six D842V mutant), PDGFRA-mutant GIST presented a greater extent of immune infiltration and cytolytic activity, which were associated with increased levels of chemokines and a greater number of mutation-derived, high-affinity neoepitopes [38].