These cells were subsequently clustered into 10 cell subgroups, including kidney epithelium, CD4 + T cell, CD8 + T cell, myeloid cell, endothelial cell, cancer cell, NK cell, fibroblast, B cell, and mast cell (Fig. 1A) by identified the marker genes (Fig. 1B; Additional file 1: Table S1). Here, CD4 is linked to cancer.