This family consists of mammalian kinetochore sub-complex proteins CENP-R, also referred to as nuclear receptor co-activator NRIF3 proteins. NRIF3 exhibits a distinct receptor specificity in interacting with and potentiating the activity of only TRs and RXRs but not other examined nuclear receptors. NRIF3 as a co-regulator that possesses both transactivation and transrepression domains and/or functions. Collectively, the NRIF3 family of co-regulators may play dual roles in mediating both positive and negative regulatory effects on gene expression. CENP-R is one of the 15 components that make up the constitutive centromere associated complex (CCAN) part of the kinetochore. A sub-complex of CCAN, consisting of CENP-P/O/R/Q/U self-assembles on kinetochores with varying stoichiometry and undergoes a pre-mitotic maturation step. Kinetochore assembly is a cell cycle regulated multi-step process. The initial step occurs during interphase and involves loading of the 15-subunit constitutive centromere associated complex (CCAN). Kinetochores are multi-protein megadalton assemblies that are required for attachment of microtubules to centromeres and, in turn, the segregation of chromosomes in mitosis.