CCL21 and idiopathic interstitial pneumonia: The mock infected primary cultures from IPF patients showed lower expression levels of MMP2 compared to the mock infected primary cultures from healthy donors with ratio of the means 0.01 (p = 0.051) (Table 4), as well as for CCR7 with ratio of the means 0.08 (p = 0.074), CCL19 with ratio of the means 0.0002 (p = 0.037) and CCL21 with ratio of the means 10−8 (p = 0.001).