Trim21 and LFG expression. (A) Results of real-time PCR-analysis of Trim21-expression after 24 h under different culture conditions. Mock, Untreated MDA-MB-231 as negative control, Trim21, 2.0 μl recombinant human Trim21 protein added to culture medium; siControl, adenoviral transfection of MDA-MB-231 with empty vector; siLFG, adenoviral transfection of MDA-MB-231 with vector coding for siRNA against LFG. (B) Expression analysis of LFG protein under different culture conditions by western blot analysis using 25 μg of total protein. a, Adenoviral transfection of MDA-MB-231 with vector coding for siRNA against LFG (24 h). b, Adenoviral transfection of MDA-MB-231 with empty vector. c, Untreated MDA-MB-231 as negative control. d, MDA-MB231 cultivated with 2.0 μg recombinant Trim21-protein in culture medium.