Immunogen sequence: RGERGSEGSP GHPGQPGPPG PPGAPGPCCG GVGAAAIAGI GGEKAGGFAP YYGDEPMDFK INTDEIMTSL KSVNGQIESL ISPDGSRKNP ARNCRDLKFC HPE. Collagen III is a fibrillar collagen that is found in extensible connective tissues such as skin, lung, and the vascula