The function of ENSG00000170899 (GSTA4, glutathione S-transferase alpha 4) is as follows. Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. This isozyme has a high catalytic efficiency with 4-hydroxyalkenals such as 4- hydroxynonenal (4-HNE). {ECO:0000269|PubMed:10329152, ECO:0000269|PubMed:20085333}.