IL10 and COVID-19: Other results of significance include the following: across PBMC samples, T cell receptor (TCR) signaling was downregulated in COVID-19 patients, immunological signatures characteristic of increased levels of pro-inflammatory interleukins, such as IL-6, IL-8, and IL-12 were upregulated in COVID-19 patients and anti-inflammatory interleukins, including IL-4 and IL-10, were downregulated in COVID-19 patients (Figure 3C).