NPSR1 and neoplasm: Most immune cells such as tumor-infiltrating lymphocytes (TILs), dendritic cells, natural killer (NK) cells, macrophages, neutrophils, and MDSC express cell-surface neurotransmitter and neuropeptide receptors, activation/blockade of neurotransmission produces protumor and antitumor immune responses in a nerve-type and tumor type-dependent manner [8].