TNF and colitis: DSS-induced colitis most often presents as inflammation in the distal colon [13], similar to human UC [14], characterized by high expression of inflammatory cytokines (eg. tumor necrosis factor alpha [TNFα] [15, 16], interleukin-1 beta [ILβ] [17]), and neutrophil infiltration (often quantified by myeloperoxidase [MPO] as a surrogate measure).