ORAI1 and malignant colon neoplasm: For example, the EP4 receptor, the predominant PGE2 receptor subtype in HT-29 and HCA-7 human colon cancer cell lines, activates PI3K and induces Ca2+ influx from the extracellular space through Orai1, resulting in ERK phosphorylation and migration of oral cancer cells (Osawa et al., 2020).