To further investigate the association between CNVs of PI3K subunits and their protein expression, and the significance of Class I subunits in DLBCL, we analyzed the expression of p110α, p110β, p110γ, p110δ, and pAKT protein in a TMA of 60 DLBCLs using IHC. The gene discussed is PIK3CD; the disease is diffuse large B-cell lymphoma.