Myelopeptide-2, a peptide isolated from the supernatant of porcine bone marrow cell cultures, can restore the mitogenic reactivity of human T lymphocytes inhibited by HL-60 leukemia cells or measles virus conditions. It also enhances depressed interleukin-2 (IL-2) synthesis and interleukin-2 receptor (IL-2R) expression, playing a role in immunity homeostasis. This compound shows potential for application in antitumor and antivirus research [1] [2].