It presumably also involves HLA class II antigens [64], as supported by genome-wide association study (GWAS) analyses (Additional file 1: Figure S12), and MYD88, CDKN2B and PIK3CD, all affected by mutations preferentially in ABC-DLBCL leading to ‘chronic active’ B cell receptor signaling [11] (see also Additional file 1: Figure S11 for pathway analyses). This evidence concerns the gene PIK3CD and diffuse large B-cell lymphoma.