PRRT2 and gastrointestinal stromal tumor: In order to evaluate the utility of PKCθ as a diagnostic marker, Kim et al. characterized the expression levels of PKCθ, KIT, CD34, α-smooth muscle actin and S-100 protein by immunohistochemistry in a larger number of GISTs (220 samples) and found that almost all the cases were PKCθ-positive or KIT-positive, which indicates that PKCθ could be an important diagnostic marker of GIST [42].