Dr. Penuela's lab is interested in the study of a novel family of channel-forming proteins, called Pannexins (Panx1, Panx2 and Panx3) that were discovered in the last decade based on their similarity to the invertebrate innexins. Although they were originally thought to be another family of gap junction proteins, we have established that their primary function is to form single membrane channels for release and uptake of ions and large molecules, such as ATP, involved in paracrine signaling. Pannexins are very important for cellular communication and are involved in early developmental events in many systems, including skin, cartilage, bone, vasculature and central nervous system, where they regulate proliferation and differentiation of different cell types. However, when expressed in adult tissues, pannexins can also have detrimental effects, for instance, facilitating cell death under ischemic conditions and malignant transformation in melanomas.