Target of rapamycin complex subunit LST8, also known as mammalian lethal with SEC13 protein 8 (mLST8) or TORC subunit LST8 or G protein beta subunit-like (GβL or Gable), is a protein that in humans is encoded by the MLST8 (MTOR associated protein, LST8 homolog) gene.[5] It is a subunit of both mTORC1 and mTORC2, complexes that regulate cell growth and survival in response to nutrient, energy, redox, and hormonal signals.[6] It is upregulated in several human colon and prostate cancer cell lines and tissues. Knockdown of mLST8 prevented mTORC formation and inhibited tumor growth and invasiveness.[7]