How the receptors receive the signals and initiate the signaling transduction processes is under intensive research, especially ACE2, the entry point for coronaviruses (e.g., HCoV-NL63, SARS-CoV and SARS-CoV-2). CD BioSciences offers a complete portfolio of solutions for uncovering the mystery of receptors and sensors including identification and characterization of receptors and generation agonists and antagonists for receptors.