GABARAP, short for GABA type A receptor-associated protein, is a member of the LC3/GABARAP protein family which evolved from yeast Atg8. It plays crucial roles in autophagy, a cellular process for degrading and recycling aged and cytotoxic components. Autophagy involves cargo capture in autophagosomes and subsequent lysosomal fusion. GABARAP is also implicated in processes like mitophagy, a form of selective autophagy, and is important for maintaining cellular homeostasis [1,2].

In multiple myeloma, loss-of-function studies have shown that deletion of GABARAP, which is commonly deleted on chromosome 17p in high-risk patients, impairs the exposure of the eat-me signal CRT on dying tumor cells. This reduces tumor cell phagocytosis by dendritic cells and the subsequent antitumor T-cell response, leading to resistance to immunogenic chemotherapy like bortezomib treatment. Mechanistically, GABARAP deletion blocks ICD signaling by decreasing autophagy and altering Golgi apparatus morphology [3].

In conclusion, GABARAP is essential in autophagy-related processes and has significant implications in cancer, particularly in multiple myeloma where its deletion is associated with poor outcomes. The study of GABARAP knockout models has provided valuable insights into its role in tumor cell immunogenicity and response to chemotherapy, highlighting its potential as a therapeutic target in this disease [3].