ACKR1 and neutropenia: In this regard, a recent GWAS on schizophrenia patients of African ancestry undergoing clozapine treatment showed a strong association of a regulatory variant in the ACKR1 gene with the development of neutropenia, a serious adverse event that results in stopping the clozapine treatment (Bentley et al., 2020; M. H. Wang et al., 2019).