DAPK1 and liver cancer: PCOLCE and TBC1D8 were selected as the most significant CEGs positively related to MAOA, and PKM was detected as the most significant CEGs negatively related to MAOA. According to Li et al, PCOLCE was significantly downregulated in liver cancer and was positively correlated with DAPK1, which is a proven prognostic factor of liver cancer.42