Any of several protein complexes required for the biogenesis of specialized organelles of the endosomal-lysosomal system, such as melanosomes, platelet dense granules, and other related organelles; acronym for biogenesis of lysosomal-related organelles complex. [ http://www.ncbi.nlm.nih.gov/pubmed/15102850 http://www.ncbi.nlm.nih.gov/pubmed/15261680 ]