TRPV4 and colitis: Activation of TRPV4 receptors in the GI tract can trigger inflammation.289 TRPV4 is expressed and functional in human colon samples, human intestinal epithelial cell lines (Caco-2 and T84), and inflamed colons of mice; 4α-phorbol-12,13-didecanoate (4αPDD) activated TRPV4 in the GI tract and increased the intracellular calcium ion concentration, which ultimately leads to chemokine release and colitis.290 Cenac et al.291 demonstrated that 4αPDD selectively activated TRPV4 in colonic sensory neurons, which affected visceral nociception and hypersensitivity.