While IL-15 and IL-16 are clustered with neutrophil-derived cfDNA in SOTRs with COVID-19, inflammatory cytokines such as IL-15, IL-6, IL-16, and MIP-1α are clustered with total (ncfDNA) and tissue-specific cfDNA from adipocytes, monocytes, erythroblasts, and neutrophils in Non-SOT COVID-19 patients. Here, IL15 is linked to COVID-19.