Analysis of the expression of the genes encoding these two cytokines (TNFSF13B and TNFSF13, respectively) by cells obtained from samples of bronchoalveolar lavage fluid of COVID-19 patients has shown that TNFSF13B is highly expressed by both macrophages and neutrophils, while TNFSF13 was expressed only by macrophages [28]. The gene discussed is TNFSF13; the disease is COVID-19.