Following optimization of initial hits the most promising of these (ML290) was found to stimulate RXFP1 by binding to the extracellular loops of the transmembrane domain and exhibited H2-RLX-like activity by increasing vascular endothelial growth factor (VEGF) mRNA expression in a secondary profiling assay using THP-1 cells (human acute monocytic leukemia cell line)18. The gene discussed is VEGFA; the disease is acute monocytic leukemia.