Although quality control of cytoskeleton-related molecules and/or cytoskeleton itself by the SIL1-HSPA5 system remains to be elucidated, further intensive analyses on the molecular machinery downstream of this system should contribute to better understanding of the mechanisms of MSS and other disorders with MR, as well as of the normal development of the cerebral cortex. This evidence concerns the gene SIL1 and Marinesco-Sjogren syndrome.