Rab4 also known as RAB4A is a member of the largest group in the Ras superfamily of small GTPases, which regulate membrane trafficking. Rab4 plays a crucial role in the regulation of endosomal trafficking, particularly in the recycling of proteins from endosomes back to the plasma membrane, which is essential for maintaining cellular homeostasis and membrane composition. This recycling process is vital for various cellular functions, including nutrient uptake, receptor signaling, and the removal of damaged proteins, thereby influencing cell survival and function. The proper functioning of Rab4 is also linked to the prevention of diseases associated with dysfunctional endosomal transport, such as neurodegenerative disorders and certain cancers.