Immunogen sequence: AQPACMAEDA FAGFLNQQQM VEGLISWRRL YCVLRGGKLY CFYSPEEIEA KVEPALVVPI NKETRIRAMD KDAKKRIHNF SVINPVP Highest antigen sequence identity to the following orthologs: Mouse - 74%, Rat - 72%. RTKN2 may play an important role in lymphopoiesis.