Determination of TRAF6 and IRAK1 mRNA levels in these CF and non-CF macrophages using RT-qPCR revealed that the CF macrophages had significantly lower levels of TRAF6 mRNA (p = 0.0103) than the non-CF macrophages, but similar levels of IRAK1 mRNA (Fig. 2b,c). Here, IRAK1 is linked to cystic fibrosis.