The Atg8 LC3 GABARAP family of proteins, a group that has structural homology with ubiquitin, connects with a large set of binding partners to function in macroautophagy (hereafter autophagy). GABARAP in tumorigenesis in vivo by delaying cell death and its associated immune-related response. GABARAPs are uniquely required for antimicrobial host defense through cytosolic distribution of interferon-inducible GTPases. GABARAPs as the first known direct interaction partners of Nef that are essential for its plasma membrane localization.