Based on the CNVs with gains in genes related to PI3K-AKT, RTK-RAS-MAPK, MYC, mTOR as upregulated oncopathways, and CNVs with losses in genes related to PTEN, FAS, FOXO1, and p53 as downregulated proapoptotic pathways, the 27 PCNSL patients were divided into two subgroups as shown in Figure 6A and 6B. The gene discussed is PIK3CD; the disease is primary central nervous system lymphoma.