ROCK2 and omphalocele: Rock1 and Rock2 show similar expression patterns in the developing embryo [6] and both the Rock1 and Rock2 single knockout mice exhibit omphalocele and open eyelids at birth [7], [8], whereas only the Rock2 null mice develop defects in development of the placenta and intra-uterine growth retardation [7], suggesting that the two genes work co-operatively in the development of these structures and have at least some non-redundant functions.