Similarity matrix analysis of the distribution of 22 immune cells showed that B cell naïve, monocyte, T cell CD8+, B cell plasma, mast cell activated, and T cell CD4+ mem clustered together, indicating that the distribution of these immune cells was similar, and the percentage of infiltration was increased in the lung tissue of COVID-19 patients (Fig 1C). This evidence concerns the gene CD4 and COVID-19.