Organoids generated from stem cells carrying pathogenic variants in several primary microcephaly genes, including ASPM, CDK5RAP2, CENPJ, CIT, KATNB1, and WDR62, have been shown to be smaller, consistent with the human phenotype (Lancaster et al., 2013; Jin et al., 2017; Li et al., 2017; An et al., 2022; Dell'Amico et al., 2023; Pallavicini et al., 2024). Here, CPAP is linked to microcephaly.