C3 and colitis: Furthermore, under active disease conditions, the expression level of following mRNA transcripts was significantly upregulated in inflamed sigmoidal biopsy samples from CD patients in comparison to colitis control patients: C1QB (5-fold), C1R (6-fold), C3 (4-fold), CFB (5-fold), CR3 (3-fold), C5aR2 (8-fold), and CD93 (6-fold) (Figure 1c).