IL6 protein levels in the supernatant of human fibroblasts following in vitro infection with CMV. Human lung fibroblasts were left untreated (mock) or infected with the CMV strain Town-eGFP. IL6 protein secretion of mock- and CMV-infected fibroblasts was analyzed by ELISA over a time period of 5 days. The arithmetic mean ± S.E.M. were calculated for each examined group and time point. Comparisons between two groups were analyzed by Student's t-test, using SPSS version 19.0 (SPSS Inc., Chicago, Illinois, USA). p values below 0.05 were considered as statistically significant. * p ≤ 0.05, ** p ≤ 0.01, *** p ≤ 0.001.