IL6 and COVID-19: In line with the herein results, patients with COVID-19 treated with MSCs showed lower levels of TNFα (Leng et al., 2020; Zhang et al., 2020), whereas they showed lower levels of IL-6 (Guo et al., 2020; Meng et al., 2020; Shu et al., 2020; Zhang et al., 2020) and higher levels of IL-10 (Leng et al., 2020) in plasma/serum samples.