Figure 4. Human saliva contains the cathelicidin LL-37. SDS-PAGE of human saliva extract and synthetic LL-37 peptide was evaluated by Western blot with rabbit antibody against full-length LL-37. Membrane was then stripped and re-probed with chicken antibody against the cathelin immature domain (CATH). Membrane was again stripped and re-probed with a unique chicken anti-LL-37 peptide antibody. Arrow at A corresponds to expected size of full-length human cathelicidin. Arrow at B (14 kDa) is intermediate size suggesting partial processing of cathelicidin. Arrow at C corresponds to 5-kDa mature LL-37 antimicrobial peptide.