Our data are in line with Chu et al. and Gonzales-Gomez et al. [5,8] analyzing the DNA methylation of CDKN2B, DAPK1, GSTP1, MGMT, MLH1, RARB, THBS1, TIMP2, and TIMP3 in PCNSL by MSP (Additional file 8) further supporting the validity of our analysis. This evidence concerns the gene TIMP3 and primary central nervous system lymphoma.