GREB1 and breast carcinoma: However, when characterized under PAM50-based subtyping, INO80 expression is significantly downregulated in basal-type breast cancer (Thang et al., 2023) Importantly, INO80 functions as a mediator of dynamic replacement of an active enhancer-based histone variant, H2A.Z, and thus as a critical regulator of enhancers close to E2 target genes such as GREB1 and TFF1, contributing to breast cancer progression (García-Pedrero et al., 2006; Papamichos-Chronakis et al., 2011; Segala et al., 2016; Thang et al., 2023).