OPCML and cancer: The log2-transformed TPM data from 33 TCGA cancer types revealed, by Wilcoxon rank-sum testing, a significant reduction of OPCML transcripts in the majority of tumors compared with their matched normal tissues (Figure 2C), with the sharpest declines in cholangiocarcinoma, esophageal carcinoma, and GBM (all p < 0.001).