Takahashi assessed immune phenotype in a sample group of COVID-19 patients and concluded that the number of non-classical monocytes and the level of CCL5 were higher in male patients, and activated CD8 T cell numbers were higher in female patients (Takahashi et al., 2020; Shattuck-Heidorn et al., 2021). The gene discussed is CCL5; the disease is COVID-19.