Taking into account the differences between the groups in the maturation of T cells (Figure 4, Table 3) the median proportion of RTE CD4+ T cells was significantly lower in COVID-19 X-ray (+) patients than in healthy control, without differences between COVID-19 X-ray (+) patients and COVID-19 X-ray (−) patients (11.6% vs. 26.8% vs. 31.2%, p = 0.0052). This evidence concerns the gene CD4 and COVID-19.