Since MYT1L patients display diverse phenotypes, including both macro- and microcephaly, and are diagnosed with different neuropsychiatric disorders like ASD and schizophrenia, future studies will be needed to clarify how specific mutations or genetic backgrounds affect these phenotypes by engineering additional mouse and human stem cell models or by generating patient-derived neurons from induced pluripotent stem cells. Here, MYT1L is linked to microcephaly.