CACNA1C and Paralytic ileus: For example, two genes, CACNB2 and CACNA1C, transcribe for voltage-dependent L-type calcium channels that are important for the influx of the calcium ions (Ca+2) required for intestinal smooth muscle contraction; selective blockage of these channels can lead to paralytic ileus (lack of movement in the intestine; (Das et al. 2018; Wegener et al. 2006).