Moreover, in agreement with previous findings, our data demonstrated that inflamed CD56dim NK cells expressing CX3CR1 (cluster 9), expand in severely infected individuals (Figure 2), probably because these cells are not recalled to the lung given the reduced levels of CX3CL1, the ligand of CX3CR1, in BALF from COVID-19 patients (36, 69). The gene discussed is CX3CR1; the disease is COVID-19.