Rab15, a member of the Rab family of small G proteins, is a low molecular weight GTP-binding protein specifically expressed in the brain [5,6]. It plays a crucial role in controlling membrane traffic, especially in the endocytic recycling pathway [1,4]. It is also involved in early endocytic trafficking, where it can counteract the stimulatory effect of Rab5 on early endocytosis [2,7].

In neuroblastoma, Rab15 alternative splicing generates multiple isoforms, and the balance of these isoforms may serve as a biomarker to distinguish tumor-initiating cells from non-tumor-initiating cells [1]. Also, its expression correlates with retinoic acid-induced differentiation of neuroblastoma cells [4]. In Ehrlichia chaffeensis infection, the bacterium's effector Etf-3 induces host RAB15 upregulation, which inhibits the fusion of E. chaffeensis-containing vesicles with lysosomes and induces autophagy, facilitating bacterial intracellular growth [3].

In conclusion, Rab15 is essential for membrane-related trafficking processes. Its role in diseases like neuroblastoma and in pathogen-host interactions as revealed through these studies provides insights into potential diagnostic and therapeutic strategies. Research on Rab15 contributes to understanding the molecular mechanisms underlying certain diseases and cell-pathogen interactions.