Regulates the membrane distribution of α(4)β(1) integrin crucial for activating the Akt survival pathways, increases apoptosis of plasma cells in germinal centers (51); initiates a cascade of events leading to apoptosis, counteracts death signals by regulating PI3K-dependent survival (52); promotes IgG1 production while inhibiting IgA immune responses in vivo and protects against the development of IgA nephropathy (53); control suppressor of cytokine signaling 3 (54). The gene discussed is PIK3CA; the disease is IgA glomerulonephritis.