NRG1 and autosomal recessive primary microcephaly: We thus blindly tested 64 cell lines after being UV treated by considering three genes with a reliable biological relevance to CS (Table 1): (i) CDK5RAP2 is involved in brain development27,28; dysfunctional alleles of CDK5RAP2 are associated with autosomal recessive primary microcephaly (MCPH327; (ii) NIPBL mutations result in Cornelia De Lange syndrome (MIM: 122470), which is characterized by smaller brain size resulted from impaired neuron production in the developing cortex29; (iii) NRG1 encodes for a multifunctional neurotrophin that mediates neurodevelopment.