Although the early application of M‐CSF peri‐transplantation mediated the antimicrobial effects described by us and lead to a lower rate of chronic GvHD, it must be noted that the therapeutic window appears to be smaller when the compound is applied later after engraftment of T cell‐replete allografts in mice (Alexander et al, 2014). The gene discussed is CSF1; the disease is graft versus host disease.