Calpain can inhibit the acetylation of MFN2 in liver I/R injury, which results in the interference of mitophagy and the damage of mitochondrial function.26 In the model of neuroblastoma SH‐SY5Y cells and cerebellar granule neurons, calpain activation down‐regulates OPA1, inhibits mitochondrial fusion and increases mitochondrial fragmentation.12, 16 We speculate that calpain affects mitochondrial fission/fusion and mitophagy by regulating OPA1, but it is not clear whether calpain has direct or indirect effects on OPA1. The gene discussed is MFN2; the disease is neuroblastoma.