PIK3CA and hypertensive disorder: Other Class I PI3K isoforms may also hold roles in hypertension, with p110δ expression being upregulated in aortas of hypertensive rats [177], while Class II PI3KC2α appears to regulate vascular smooth muscle contraction and play a role in spontaneous hypertension in rats via a Ca2+-PI3KC2α-RHO axis [178–180].