ASH2 (absent, small, or homeotic discs 2) is a subunit of a human Set1-like histone methyltransferase (HMT) complex. The Set-1 like complexes are responsible for mono-, di-, and tri-methylation of histone H3 K4. ASH2 associates with a multitude of proteins in a number of Set1-like complexes which include various combinations of MLL, MLL2, MLL3, MLL4, RBBP5,WDR5, hDPY-30, hSwd2, CXXC1, HCF1, Menin, PTIP, PA1, NCOA6, and UTX.