Importantly, PI3Ks are expressed not only in the cancer cells, but also in the non-neoplastic cells, in which PI3K inhibitors contribute to their pro- or anti-tumor effects, and they can be used to improve the response to immunomodulatory and immunotherapeutic agents [9,10,11,12,13,14,15,16,17]. The gene discussed is PIK3CD; the disease is cancer.