PIK3CB and colitis: While these are common effects for many types of drugs, the mechanism for idelalisib-induced colitis is thought to be mediated at least in part through the enhanced inflammatory response occurring in response to gut pathogens [123], and there is some evidence that points to this dose-limiting toxicity being a PI3K class effect, since PI3Ks play roles in gut immunity, motility and neuro-transmission [124].