CCL18 and idiopathic interstitial pneumonia: Pronounced differences in the serum CCL18 levels were observed between genotypes of the rs2015086 polymorphism in the IPF patients of the derivation cohort; TT 585 ng/mL (IQR 340 –793) and CT 817 ng/mL (IQR 681 – 1278), p = 0.002, as shown in Figure 2C. No differences were present in the baseline characteristics between the patients with CT and TT genotypes of rs2015086, as shown in Table 1.