PTGER2 and cancer: Previous studies showed that platelets contribute to regulate PTGS2 (COX-2) expression in cancer cells (Dovizio et al., 2015) and that COX-2 overexpression is a hallmark of tumor invasion, metastasis, and poor prognosis in colorectal cancer and other cancer types (Singh, Berry, Shoher, Ramakrishnan and Lucci, 2005; Szweda, Rychlik, Babińska and Pomianowski, 2019; Sheng et al., 2020; Kolawole and Kashfi, 2022).