Ras-related protein Rab-40A is a protein that in humans is encoded by the RAB40A gene.

This gene encodes a member of the Rab40 subfamily of Rab small GTP-binding proteins that contains a C-terminal suppressors of cytokine signaling box. [provided by RefSeq, Apr 2010].
Function: May be a substrate-recognition component of a SCF-like ECS (Elongin-Cullin-SOCS-box protein) E3 ubiquitin ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (By similarity).