In this study, we report a full spectrum, mainly focused on the dynamics of peripheral immune cells, the expressions of HLA‐G and its receptors (ILT2, ILT4 and KIR2DL4) in peripheral immune cells, and the outcomes of a patient infected with SARS‐CoV‐2 (critical COVID‐19) during the 23‐day hospitalisation. The gene discussed is LILRB2; the disease is COVID-19.