PRL regulates expression of genes involved in inflammation, proliferation, and cell survival. A. K4IM synoviocytes were treated in triplicate with TNF-α (10 ng/mL) or PGE2 (1 μM) for 24 hours. PRL-R was measured by RT-qPCR. ***p < 0.001. B. cDNA from K4IM synoviocytes treated with rhPRL (1 μg/mL, 24 hours) was analyzed on JAK/STAT signaling pathway qPCR arrays. Gene expression data was normalized to 3 housekeeping genes and the genes most highly regulated by rhPRL are displayed.