Diagnostic methods involving human growth factor huXAG-1

A diagnostic method comprising:

• (a) measuring the protein level of a polypeptide in a sample from an individual, wherein said sample is colon tissue, and wherein said polypeptide has an amino acid sequence at least 95% identical to a sequence selected from the group consisting of:
• (i) amino acids from about −20 to about 155 in SEQ ID NO:2;
• (ii) amino acids from about −19 to about 155 in SEQ ID NO:2;
• (iii) amino acids from about 1 to about 155 in SEQ ID NO:2;
• (iv) the amino acid sequence of a full-length polypeptide having the amino acid sequence encoded by the cDNA clone contained in ATCC Deposit No. 97641;
• (v) the amino acid sequence of a mature polypeptide having the amino acid sequence encoded by the cDNA clone contained in ATCC Deposit No. 97641;
• and
• (b) comparing said protein level of said individual with a standard huXAG-1 (SEQ ID NO:
• 2) protein level, whereby an increase or decrease in the protein level over said standard is indicative of the presence or absence of a huXAG-1-related disorder, wherein said protein level of said individual is detected with an antibody.