Antigen and Rh-negative

Antigen noun - Any substance (as a toxin or enzyme) that stimulates an immune response in the body (especially the production of antibodies).

Rh-negative and antigen are semantically related in blood group antigen topic. In some cases you can use "Rh-negative" instead a noun "Antigen".

Rh-negative adjective - Of persons (or their blood) lacking the Rh factor present in their red blood cells.

Antigen and Rh-negative are semantically related in blood group antigen topic. You can use "Antigen" instead a noun phrase "Rh-negative".