Updated project metadata. We have found Rab39a to be important in dendritic cells to promote antigen crosspresentation. As Rab39a is a Rab GTPase, we sought to determine how it influenced the contents of phagosomes. Thus we used SILAC using Rab39a CRISPR KO or reconstituted cells to determine phagosomal protein differences using a proteomics based approach.