GAPDH and chronic rhinosinusitis with nasal polyps: However, the expression pattern using ACTB was different from using RPLP0 and RPLP1. Although IFN-γ and IL-17A did not show the differences, the genes exhibited similar expression trends when we normalized using RPLP0 and RPLP1. Conversely, when ACTB and GAPDH were used, particularly wide variation in gene expressions was observed in nasal polyps from the CRSwNP group compared to the other RGs (Fig. 3C,D), and the trend was seen in all the four genes.