The retinoic acid (RA) signaling pathway is crucial for many biological processes. The RA transporter, Cellular Retinoic-Acid Binding Protein 2 (CRABP2), is abnormally expressed in various tumor types. CRABP2 presents significant effects on tumorous behaviors and functions, including cell proliferation, apoptosis, invasion, migration, metastasis, and angiogenesis. The tumorigenesis mechanism of CRABP2, as both suppressor and promotor, is complicated, therefore, there remains the need for further investigation. Elucidating the regulating mechanisms in a specific stage of the tumor could facilitate CRABP2 to be a biomarker in cancer diagnosis and prognosis. Besides, clarifying the pathways of CRABP2 in cancer development will contribute to the gene-targeted therapy. In this review, we summarized the expression, distribution, and mechanism of CRABP2 in solid tumors. Illuminating the CRABP2 signaling pathway may benefit understanding the retinoid signaling pathway, providing a useful biomarker for future clinical trials.

视黄酸（RA）信号传导途径对于许多生物学过程至关重要。RA转运蛋白，细胞维甲酸结合蛋白2（CRABP2）在各种肿瘤类型中异常表达。CRABP2对肿瘤行为和功能（包括细胞增殖，凋亡，侵袭，迁移，转移和血管生成）具有重要影响。CRABP2既是抑制因子又是启动子，其致癌机制十分复杂，因此，仍需进一步研究。阐明肿瘤特定阶段的调节机制可以促进CRABP2成为癌症诊断和预后的生物标志物。此外，阐明CRABP2在癌症发展中的途径将有助于基因靶向治疗。在这篇评论中，我们总结了表达式，分布，实体瘤中CRABP2的表达及机制 照亮CRABP2信号通路可能有助于理解类维生素A信号通路，为将来的临床试验提供有用的生物标记。