cAMP production Induced by Relaxin‑3 and Neutralization by Human Relaxin‑3 Antibody. Recombinant Human Relaxin‑3 (Catalog # 3107-RN) induces cAMP production in the THP‑1 human acute monocytic leukemia cell line in a dose-dependent manner (orange line), as measured by cAMP Parameter Assay Kit (Catalog # KGE002B). cAMP production elicited by Recombinant Human Relaxin‑3 (25 ng/mL) is neutralized (green line) by increasing concentrations of Mouse Anti-Human Relaxin‑3 Monoclonal Antibody (Catalog # MAB31071). The ND50 is typically 1-5 µg/mL.