Comparing the effect of complement C3a receptor (C3aR) to that in the absence of C3aR, NETs are more likely to be generated under the effect of C3aR, leading to the activation of coagulation in small intestinal tumors, a hypercoagulable state and thrombosis (Wiedmer et al., 1986). This evidence concerns the gene C3AR1 and small intestine neoplasm.