Therefore, to elucidate the interactions between immune cells and tumor cells, further investigation of oncogenic signaling pathways, the tumor mutational burden, and mutation-associated neoantigen-specific T cells seems to be warranted in patients with UTUC, including the types of immune cells infiltrating tumor tissues and interrelations among PD-L1, TAMs, MDSCs, and Tregs in the tumor microenvironment. This evidence concerns the gene CD274 and renal pelvis/ureter urothelial carcinoma.