Similarly, leukocyte migration is also regulated by hematopoietic cell-specific lyn-substrate 1, an actin-binding protein encoded by HCLS1. Moreover, the latter protein is involved in differentiation of myeloid cells and cases of underexpression have been associated with human congenital neutropenia (Samareh-Abolhasani et al., 2013; Castro-Ochoa et al., 2018). This evidence concerns the gene HCLS1 and severe congenital neutropenia.