Therefore, VitD may exert its regulatory effects mainly through ERBB2, EGFR and MAPK8 mediated activation of the ErbB and MAPK signaling pathways to control the cytokine storm process in COVID-19 patients and to ameliorate pulmonary fibrosis, and activation of osteoimmune mechanisms to regulate the structural integrity of bone. The gene discussed is ERBB2; the disease is pulmonary fibrosis.