Despite suggestive recent evidence of potential efficacy of MSC administration in pre-clinical models of influenza respiratory viral lung infections, there are limited published clinical data available. A recently published single-centre open-label pilot investigation from the YouAn Hospital in Beijing (China) administered BM-MSCs to seven patients with COVID-19 pneumonia with differing degrees of severity including one patient with critically severe disease requiring care in the intensive care unit (ICU) [47]. The MSCs were given as a single intravenous administration at a dose of 106 cells·kg−1 body weight in 100 mL saline at various times after initial symptomatic presentation. The MSCs were assessed by RNA sequencing for expression of ACE2 or TMPRSS2 prior to administration and each was found to be minimally expressed (in one out of 12 500 cells and seven out of 12 500 cells, respectively), although the RNA sequencing results were not validated for gene (quantitative reverse transcription PCR) or protein expression.