Persuasive preclinical data support the targeting of specific members of the mitogen-activated protein kinase (MAPK) (e.g., p38-α) and PI3K/Akt/mTOR (p110δ) pathways but none of the inhibitors have progressed to phase III clinical studies due to lack of efficacy in RA patients and concerns about toxicity (reviewed in [2, 3]). The gene discussed is PIK3CD; the disease is rheumatoid arthritis.