PIK3CA and Dry skin: PI3K inhibitors also significantly increased the risk of pruritus and dry skin (RR 1.63, 95% CI 1.14–2.33, p = 0.007; RR 3.34, 95% CI 2.30–4.85, p < 0.00001), with incidences of 13.4% (284/2115) and 9.8% (141/1436) in the treatment group.