CP and neoplasm: Extrapolating from our findings that mRNA for the dermcidin gene (Schittek et al, 2001), which encodes the proteolysis-inducing factor (PIF) core peptide (PIF-CP), is present in both gastrooesophageal tumour and adjacent non-tumour tissue, EA Rapoport suggests that PIF may be generally involved in muscle breakdown via production of PIF in tissues requiring amino acids for tissue regeneration, for example, in liver regeneration.