Immunogen sequence: QLGSPQVRAG SAGQTFLGPS SAPVSTDSPS LGGSQTLFHT SGQPRADNPS PNLMPASAQA QNAQRALAGV VLPSQGPGGA SELSSAHQLQ QIAAKQKREQ MLQNPQ. This protein is the human homolog of mastermind, a Drosophila protein that plays a role in the Notch signaling pathw