KNL1 and microcephaly: Extensive studies have demonstrated that numerous causative factors can lead to microcephaly, including genetic mutations (e.g., ASPM, CDK5RAP2, IER3IP1, Asparaginyl -tRNA synthetase1 (NARS1), KNL1, etc.), and prenatal exposure to toxins or pathogens (e.g., Zika virus) (Jayaraman et al. 2018).