Latexin, the endogenous protein inhibitor of the A/B subfamily of metallocarboxypeptidases, is expressed in small nociceptive neurons in sensory ganglia and in a subset of neurons in the telencephalon. Recently, the latexin (Lxn) gene was identified as a potential tumor suppressor in several types of solid tumors and lymphoma, and Lxn expression was found to be absent or downregulated in leukemic cells.