Single-cell RNA-sequencing dissection of human ccRCC tumours revealed that a population of tumour-associated macrophages (TAM) that express TREM2, APOE and C1Q genes is associated with recurrence after surgery13 and that a similar population of TAM2-like cells is enriched in late stage and metastatic tumours versus early stage tumours14, implicating TAMs in processes associated with aggressive ccRCC disease. This evidence concerns the gene TREM2 and nonpapillary renal cell carcinoma.