The top 10 genes that had the highest Log2FC in FFPE tissue that were also significantly dysregulated in the same direction in the plasma were identified for DLBCL versus controls (upregulated: LAT2, SEMA4A, LOX, ADAM8, PTAFR; downregulated: FABP4, FAM107A, LIFR, LPL, FMO2), for PMBCL versus controls (upregulated: PTGIR, CLIP2, ANKRD33B, ZNF185, TREM1; downregulated: IGLC2, LIFR, PDK4, PLAC8, IGKC), and for PMBCL versus DLBCL (upregulated: ANK1, PTGIR, ANKRD33B, SPINT2, UNC13B; downregulated: PLEKHG1, PLAC8, FOXP1, CCND2, PRDX2). The gene discussed is IGKC; the disease is diffuse large B-cell lymphoma.