ARRB1 and AIDS dementia complex: The non-visual beta-arrestin-1 (also called arrestin-2 and encoded by the ARRB1 gene) and beta-arrestin-2 (also called arrestin-3 and encoded by the ARRB2 gene) belong to a family of four cytosolic adaptor proteins, known for their role in the desensitisation of the seven-transmembrane receptors.11,12 Beta-arrestins can also recruit cytoplasmic proteins and modulate downstream signalling pathways.12–16 Here, we describe the clinical potential of beta-arrestin-1 as a diagnostic marker to discriminate ADC from SCC, using tissue samples from independent patients’ cohorts.