DLBCL patient samples exhibit low SMAD1 expression and high SMAD1 promoter hypermethylation. (A) Immunohistochemical SMAD1 staining of DLBCL patient samples derived from testis, lung, and lymph nodes, as well as a gastric marginal zone lymphoma (MZL) sample. Normal lymph nodes are shown as control. Scale bars, 100 μm. (B) Methylation analysis by bisulfite sequencing of region 2 within the SMAD1 promoter in DLBCL, MZL, normal B-cell, and lymph node samples. Each circle represents 1 CG dinucleotide. Each line represents 1 clone. Two or 3 clones were sequenced per sample. ●, methylated cytosine; ○, unmethylated cytosine; ×, aligned mismatches between genomic and bisulfite sequences. The red asterisk marks the patient sample that was further used for patient-derived xenotransplantation experiments in Figure 6.