Consistent with the results of DNA methylation analysis, ATRX immunohistochemistry was performed (mouse monoclonal, clone BSB-108, dilution 1:2000, Bio SB, Santa Barbara, CA, USA) and showed a near complete loss of ATRX nuclear expression in tumor cell nuclei compared to non-neoplastic cells (Figure 1(B)). The gene discussed is ATRX; the disease is neoplasm.