Likewise unexpectedly, we found no associations between gastrointestinal transit times and TNF-α, even though this cytokine has been associated with prolonged transit time in ulcerative colitis [6], and accumulating preclinical evidence shows that this potent pro-inflammatory cytokine may play an active role in modulation of motility patterns within the gastrointestinal tract. Here, TNF is linked to ulcerative colitis.