The preclinical data on MSCT decreasing TNF‐α and IL‐6 levels, two pro‐inflammatory cytokines highly expressed during cytokine storm,95 have been quite consistent, and clinical MSCT data from the other immune/inflammatory diseases—particularly GVHD which have had long follow‐up periods—as well as the two recently published viral pneumonia trials, support the relative safety of MSCT even if efficacy may be more difficult to interpret. Here, IL6 is linked to graft versus host disease.