In Yan et al (2019a), a limited comparison of CD34‐HIS mice and BLT‐HIS mice was undertaken and BLT‐HIS mice showed clear evidence of CRS and no GVHD, whereas CD34‐HIS mice did not show any difference as compared to control treatment, suggesting that the CD34‐HIS mouse does not show a clear signal for CRS and may not be an appropriate model. Here, CD34 is linked to congenital rubella syndrome.