HomeNursing questions The gene in ABO system.. A.B.O publisher :NIL NAM -July 03, 2017 The gene in ABO system: a. A.B.C b. A.B.O*** c. A.B.H d. A.B.D. Labels Nursing questions Facebook Twitter Share:The gene in ABO system.. A.B.O Facebook Twitter WhatsApp Pinterest LinkedIn Reddit Tumblr Telegram Email