The Human leukocyte antigen (HLA) system is of major importance for immunological communication between immune and body cells dominating all other check point control systems.

Therefore it is also called Major Histocompatibility Complex (MHC).

Every human being has its unique HLA code.

Any cell with an aberrant or missing HLA code will be eliminated by the immune system.

Only during pregnancy this mechanism is blocked by embryonic HLA’s to allow the baby, which is 50% “foreign” to mother’s immune system, not to be rejected and survive.

Cancer must misuse this embryonic mechanism not to be eliminated by the immune system.

Despite detailed knowledge about the fundamental role of embryonic HLA’s in pregnancy, its major importance has not yet been explored and exploited for cancer treatment.