These circuits act through neurotransmitters (catecholamines, acetylcholine) and neuropeptides (substance P [SP], calcitonin gene-related peptide [CGRP]) to foster tumor growth and angiogenesis, facilitate perineural invasion, and enable immune evasion by recruiting suppressive myeloid and lymphoid populations and by inducing checkpoint molecule expression. Here, TFF2 is linked to neoplasm.