TNF and diabetes mellitus: Besides, individuals with DM have been shown to have elevated levels of proinflammatory cytokine, especially IL-1, IL-6, and TNF-α, and different markers such as C-reactive protein, D-dimer, and fibrinogen, which may further prolong cytokine storms and lead to severe illness in DM individuals with COVID-19 infection (Huang I. et al., 2020; Han et al., 2021; Malik et al., 2021).