PIK3CB and neoplasm: Beclin 1 was identified as a BCL-2 interaction factor in the yeast two-hybrid screen in 1988.512,513 Human Beclin 1, the mammalian orthologue of yeast Atg6, consists of a BCL-2-homology 3 structural domain,514 a flexible helical domain,515 a coiled coil domain,516 and an evolutionarily conserved domain.514 Moreover, Beclin 1 contains a leucine-rich nuclear export signal that is essential for its autophagic and tumor suppressor functions.517 Beclin 1 is phosphorylated by ULK1 and acts as an integral component of the PI3K complex to localize autophagy proteins to the phagosome.