Many COVID-19 patients have been diagnosed with abnormal production of serum cytokines and chemokines such as interleukin-6 (IL-6) [10, 19], IL-1α [11], IL-1β [12], IL-2 receptor (IL-2R) [13], IL-3 [14], IL-7 [20], IL-8 [15], IL-10 [21], IL-13 [22], IL-18 [12], IL-37 [18], tumor necrosis factor-α (TNF-α) [19] and transforming growth factor-β [23], especially in severe and critical cases. Here, IL10 is linked to COVID-19.