**4. Conclusions**

In COVID-19 pandemic, in the field of medicine, an unprecedented upheaval has been observed. For example, it has been observed that cancer and cardiovascular diseases are vulnerable to COVID-19. Also, unfavorable courses and severe outcomes of COVID-19 have been observed in cancer and cardiovascular diseases. In addition, COVID-19 patients have an increased risk of cancer prevalence and death. Establishing clinical guidelines in COVID-19 pandemic is essential for high-risk patients. For example, monitoring protocols and clinical cares have been implemented for cardiooncology care during COVID-19 pandemic. In order to better understand the effects of cardio-oncology and COVID-19 on each other, some common biological pathways like mitogen-activated protein kinase **(**MAPK) pathway, PI3K/AKT/mTOR pathway, JAK– STAT signaling pathway, TLRI signaling, and NF-κB pathway have been explained.
