Under high‐glucose culture conditions, the lactylation of RCC2 activates MAD2L1 expression and promotes the proliferation of breast cancer cells (Figure 7I), elucidating the intriguing phenomenon observed in mice.[12] We hypothesize that RCC2 as a substrate protein localized on chromatin, recruits free RBPs after being lactylated, facilitating the spatial interaction between RBPs and pre‐mRNA to form a complex. Here, MAD2L1 is linked to breast cancer.