Activating mutations of PI3K subunits (PIK3CA amplification/activating mutation) are identified in 6% of ABC DLBCL but not GCB, others (PTEN deletion) are present in both ABC and GCB (9%–11%) (Lenz et al., 2008a; Pfeifer et al., 2013; Chapuy et al., 2018; Schmitz et al., 2018; Wang et al., 2018). The gene discussed is PIK3CD; the disease is aneurysmal bone cyst.