MGMT and colorectal carcinoma: MGMT expression of the TCGA CRC samples (as assessed by Agilent expression microarrays), also exhibited a bimodal distribution, with 81.3% of the samples with an expression level above 0.36 (relative to the average expression of MGMT in 22 normal colon samples, Figure 4a), used as cut-off for MGMT-silencing because it coincided with the valley separating the two expression peaks.