ITPR3 and cancer: Unfortunately, the limited access of inhibitors either for IP3R or for MCU has prevented the development of pharmacokinetics and pharmacodynamics experiments in vivo, hindering the understanding of the real potential of this pathway as a therapeutic option, as has been achieved for other ion channels and the SERCA pump (118) Thus, the design of new drugs targeting the functional Ca2+ coupling between ER and mitochondria is fundamental to further understand the role of this pathway in phenomena such as angiogenesis, metastasis, chemoresistance, and cancer relapse.