The terms immunogen and antigen were not distinguished until 1959
An immunogen is any substance that generates B-cell (humoral/antibody) and/or T-cell (cellular) adaptive immune responses upon exposure to a host organism.[1][2] Imm
Cells in the APUD system may include melanocytes
Melanocytes are melanin-producing neural crest-derived cells located in the bottom layer (the stratum basale) of the skin’s epidermis, the middle layer of the eye (t