We recently assigned the human gene (GLCLC) that encodes the catalytic subunit of gamma-glutamylcysteine synthetase (glutamate-cysteine ligase, E.C. 6.3.2.2) to human chromosome 6p12. Here we specify the chromosomal sublocalization of the human gene (GLCLR) that encodes the regulatory subunit of E.C. 6.3.2.2 to chromosome 1p21.