The successful transition of the drug KarXT, a coformulation containing the CHRM1/CHRM4 agonist, through a large phase 2 trial (Brannan et al., 2021) and a phase 3 trial raises the prospect of a new treatment for schizophrenia that is not a dopamine D2 receptor antagonist that may also have some partial agonist properties. This evidence concerns the gene CHRM1 and schizophrenia.