Since mutant HTT is also expressed in glial cells and glial dysfunction contributes to HD neuropathology (Shin et al., 2005; Bradford et al., 2009, 2010; Khakh and Sofroniew, 2014; Huang et al., 2015; Diaz-Castro et al., 2019; Lee et al., 2022), it is interesting to investigate whether mutant HTT affects glial development, thereby contributing to early neuronal development defects. The gene discussed is HTT; the disease is Huntington disease.