該基因編碼的蛋白質屬于高度保守的細胞周期蛋白家族，其成員在細胞周期內具有顯著的蛋白質豐度周期性。細胞周期蛋白起著調節CDK激酶的作用。不同的細胞周期蛋白表現出不同的表達和降解模式，這有助于每個有絲分裂事件的時間協調。該細胞周期蛋白與CDK4或CDK6形成復合物，并作為該復合物的調節亞單位發揮作用，其活性是細胞周期G1/S轉換所必需的。這種蛋白與腫瘤抑制蛋白Rb的磷酸化相互作用并參與其中。小鼠同源基因敲除研究提示該基因在卵巢顆粒和生殖細胞增殖中的重要作用。該基因在卵巢和睪丸腫瘤中高水平表達。該基因突變與巨頭畸形多發性多指狀腦積水綜合征3（MPPH3）有關。
The protein encoded by this gene belongs to the highly conserved cyclin family, whose members are characterized by a dramatic periodicity in protein abundance through the cell cycle. Cyclins function as regulators of CDK kinases. Different cyclins exhibit distinct expression and degradation patterns which contribute to the temporal coordination of each mitotic event. This cyclin forms a complex with CDK4 or CDK6 and functions as a regulatory subunit of the complex, whose activity is required for cell cycle G1/S transition. This protein has been shown to interact with and be involved in the phosphorylation of tumor suppressor protein Rb. Knockout studies of the homologous gene in mouse suggest the essential roles of this gene in ovarian granulosa and germ cell proliferation. High level expression of this gene was observed in ovarian and testicular tumors. Mutations in this gene are associated with megalencephaly-polymicrogyria-polydactyly-hydrocephalus syndrome 3 (MPPH3).