As mentioned above, the expression levels of HMOX1, LTC4S, and ACTB seem to have negative correlation relationships with the risk of cerebral ischemia (Freiberg et al., 2010; Nitti et al., 2018; Cui et al., 2020; Yang et al., 2020), the significant downregulation of HMOX1, LTC4S, and ACTB in PBMC samples from COVID-19 positive patients may indicate possible molecular mechanisms between COVID-19 and stroke. Here, HMOX1 is linked to brain ischemia.