MAD2L1-binding protein （MAD2L1BP） is a member of the MAD2L1BP family.MAD2L1BP is a binding protein of the MAD2 mitotic arrest deficient-like 1 （MAD2/MAD2L1）. MAD2 is a fundamental factor of the spindle checkpoint which delays the onset of anaphase until all the kinetochores are connected to the spindle. The MAD2L1BP protein acts to curb the spindle checkpoint and allow mitosis to proceed through anaphase by binding MAD2L1 once it dissociated from the MAD2L1-CDC20 complex. For the duration of the cell cycle， MAD2L1BP levels increase and then remain constant until late mitosis after which they drop.
