RPRD1B and cancer: To further investigate the role of APLN in the KIRC cancer-stromal homeostasis, pharmacological inhibition tests were performed by injecting MM54 (cyclo[1-6]CRPRLC-KH-cyclo[9-14]CRPRLC), an established apelin receptor (APJ)-specific antagonist (Macaluso et al., 2011), intraperitoneally into the KIRC model mice.