RET and neoplasm: Variants associated with MEN2B have also been demonstrated to suppress expression of genes required for recruitment and action of NK cells and T-cells in the tumour microenvironment (TME), such as chemokine C-X3-C motif ligand 1 (CX3CL1), with inflammatory cell infiltrates only seen in MEN2A/FMTC-associated tumours [20].