And that means if it doesn't have that gene it cannot actually express and produce any one of these antigens. And in such a case if the male parent doesn't have that gene and the female parent doesn't have that gene and they essentially made, they will produce an offspring, an individual in which we basically have neither antigen A nor antigen B on the membrane of that red blood cell. And in that case our immune system will produce both antibodies against antigen A and against antigen B. And this is what we call a blood type O. So such an individual lacks both antigens and their red blood cells on their red blood cells. And so the immune system produces antibodies against antigen A as well as against antigen B.