Moreover, we also assessed the correlation between the tOPN and OPN4 expression levels and influenza viral load in the clinical samples, regardless of their severity, which revealed no significant association (R2 = 0.0402, p = 0.16 and R2 = 0.0004, p = 0.83, respectively) (Figure 2C,D). The gene discussed is OPN4; the disease is influenza.