GL50-B B7-H2 genetic mapping LICOS ICOS-L|B7-H2|GL50-B|B7h|GL50|B7RP-1|LICOS B7h Gene protein coding gene MGI:1354701 GL50 http://identifiers.org/mgd/MGI:1354701 icos ligand Icosl B7RP-1 O ICOS-L +