Previous studies have reported a significant decrease in LYM counts in patients infected with influenza A [8, 21, 22], but few studies have examined LYM counts in patients infected with influenza B. According to Nichols et al. [23], LYM induced self-apoptosis by regulating the expression of FasL on the cell surface and released soluble FasL after influenza infection, leading to a decrease in the LYM count. The gene discussed is FASLG; the disease is influenza.