OPA1 and colorectal carcinoma: Meanwhile, the expressions of phosphorylated Drp1 (p-Drp1, S616) and Fis1 were decreased, while OPA1, MFN1 and MFN2 were increased in HCT116 and RKO cells with PTPLAD1 overexpression, and a converse effect was found in CRC cells transfected with two siRNAs against PTPLAD1 (Fig. 3C), suggesting that PTPLAD1 negatively regulates mitochondrial fission in CRC.