iRhoms: ERADicating the messenger in growth control signaling.

iRhoms are inactive rhomboid-like pseudoproteases that lack essential catalytic residues. Although iRhoms are highly conserved in metazoan species, little is known about their function. In a recent issue of Cell, Zettl et al. (2011) show that iRhoms regulate growth factor signaling through endoplasmic reticulum-associated protein degradation (ERAD).