RPTOR and microcephaly: Moreover, inactivation of mTORC1 signalling in Rptor knockout mice results in microcephaly associated with reduced neural progenitor cell proliferation, slowing of neural progenitor cell cycle, and increased neuroblast apoptosis, as well as proteinuria and progressive glomerulosclerosis (Godel et al., 2011; Cloetta et al., 2013).