The functionality of the large number of proteins enriched within UC samples was studied further, identifying ABC transporters for branched-chain amino acids (LivF/G/H/K/M)37, phosphate (PstA/B/C/S)38, and adenosine (NupA/B/C, BmpA)39, each of which has been linked to colitis. Here, ABCG2 is linked to colitis.