Figure 1  The procalcitonin (ProCT) molecule and its components. AminoproCT 				= amino terminus of procalcitonin; immature CT = the 33 amino acid, 				non-amidated CT; CCP-I = calcitonin carboxyterminus peptide-I. In normal 				people, in addition to the free, active, mature CT, small amounts of ProCT, 				aminoproCT, CCP-I, the conjoined CT:CCP-I peptide, and the immature CT 				circulate [18]. The amino acid sequence of the rat 				mature CT is very similar to that of humans, and the sequence of hamster CT, 				although not yet known, reveals, by immunoassay studies, a marked homology with 				the rat.