CLDN5 and gastrointestinal stromal tumor: Moreover, marker gene expression analysis for each cluster revealed that B cells highly expressed MS4A1; EC highly expressed PECAM1 and CLDN5; SMC highly expressed COL1A2, ACTA2, CNN1, and TAGLN; NK cells highly expressed NKG7 but not CD3D; myeloid highly expressed LYZ; T cells highly expressed CD3D, DC highly expressed CD14 and FCGR3A; fibroblast highly expressed KIT, ANO1, and COL8A1, which were marker genes for GIST (Fig. 1d).