CST3 and COVID-19: Meanwhile, we found that creatinine (p < 0.001), trioxypurine (p = 0.003), cystatin C (p = 0.004), and estimated glomerular filtration rate (eGFR) (p < 0.001) values in the positive group significantly differed compared to those in the negative group, and this suggests that renal injury may be related to cardiac injury in patients with COVID‐19.