Cancer is currently one of the main diseases causing a high number of deaths per year. Therefore, there is an urgent need to understand better the diversity of tumors. Moreover, there is also a need to further initiate the development of effective therapeutic tools or combinations of currently existing medicines to target cancer in novel ways. Mitochondria are highly dynamic organelles that provide energy for cell growth, proliferation, differentiation, invasion, metastasis, survival, and death. When cells become cancerous, the morphology, cellular location, and metabolic mode of the mitochondria change accordingly. These mitochondrial changes can have two opposing effects on cancer: pro-cancer and anticancer effects. Specifically, mitochondria play roles in the fight against cancer by participating in processes such as ferroptosis, mitophagy, and antitumor immunity. Meanwhile, cancer cells can also enslave mitochondria to give them the conditions necessary for growth and metastasis. Moreover, through mitochondria, cancer cells can escape from immune surveillance, resulting in their immune escape and enhanced malignant transformation ability.

Understanding the complex role of mitochondria in cancer biology is critical and may help identify novel therapeutic and preventative strategies for malignant tumors. Mitochondrial quality control (MQC) is a group of adaptive responses that regulate mitochondrial protein turnover, mitochondrial biogenesis, mitochondrial fusion, mitochondrial fission, mitophagy, and mitochondria-dependent cell death. The main consequences of MQC are the rapid removal of defective mitochondrial debris and the timely replenishment of the mitochondrial network. These biophysical processes protect the mitochondria from damage and therefore contribute to tumorigenesis. When these adaptive responses fail, programmed cell death by apoptosis or necroptosis is activated, and damaged mitochondria become the inducers of cell death, enabling the sequestration of injured or dysfunctional cancer cells. However, the roles of MQC in tumorigenesis and/or cancer cell death have not been fully explored. Besides, given the important role played by mitochondria in cancer biology, it remains of outstanding interest to design, develop, and validate pharmacologic and non-pharmacologic preventive approaches for the treatment of cancer with a focus on MQC.

The aim of this Special Issue is to figure out the functional importance of MQC in cancer biology. It aims at spreading the knowledge that MQC participates in a number of biochemical pathways important for the survival or death of tumour cells. Submissions should consider MQC as a central target in therapeutics. We strongly encourage submissions of both original and review articles.

Potential topics include but are not limited to the following:

• Innovative aspects of MQC (e.g., mitochondrial fission, fusion, mitophagy, and mitochondrial metabolism) in human cancers
• Clinically relevant information on the effects of therapies for cancer with a focus on MQC
• Recent advances in the knowledge and understanding of MQC in human cancers
• Pharmacologic and non-pharmacologic preventive approaches with a MQC focus for cancer treatments