Since its discovery in Xenopus embryos, the significance of EMI1 has been elevated through numerous cell-cycle and cancer biology studies, including a live cell imaging study where EMI1 was identified as a key “point of no return” step for cell cycle reentry by inactivating the APC/C at the G1/S boundary (Di Fiore and Pines, 2008; Shimizu et al., 2013; Barr et al., 2016; Cappell et al., 2016; Guan et al., 2016; Vaidyanathan et al., 2016; Marzio et al., 2019; Moustafa et al., 2021). Here, FBXO5 is linked to cancer.