Tumor formation and antitumor immunity; the overlooked significance of histamine

HA is a biogenic amine, widely distributed throughout the body. Given the observations that HA, the decarboxylated amino acid histidine, can be induced and made available in an unstored, diffusible form in tissues undergoing rapid growth (such as tumors and regenerating tissues), it could have a role in antitumor response beyond the well-studied inflammatory and allergic responses.