. "\"Any process that stops, prevents, or reduces the frequency, rate, or extent of a humoral immune response mediated by circulating immunoglobulin.\" [GOC:add]" . . "negative regulation of humoral immune response mediated by circulating immunoglobulin" . "down regulation of humoral immune response mediated by circulating immunoglobulin" . "down-regulation of humoral immune response mediated by circulating immunoglobulin" . "downregulation of humoral immune response mediated by circulating immunoglobulin" . . . . "inhibition of humoral immune response mediated by circulating immunoglobulin" .