tokens: DHEA binding sites were examined using a whole-cell binding assay in a human T lymphoid cell line , PEER , revealing that a single class of high-affinity binding sites for DHEA ( dissociation constant = 7.4 +/- 0.53 nmol/L , mean +/- SE , n = 4 ) was greatly increased when treated with DHEA , phorbol-12-myristate-13-acetate , and the Ca2+ ionophore A23187 .