BSG and psychiatric disorder: Though CD147 expression was never studied in mental illness, in animal models psychological stress up-regulated CD147 expression through the increased release of norepinephrine and the activation of the Beta-Arrestin1/ERK pathway, a mechanism implicated in the detrimental effects that stress exerts on occurrence and prognosis of malignant tumors29, and suggested to play a role in enhancing susceptibility to SARS-CoV-2 infection30.