CD63 and metabolic dysfunction-associated steatotic liver disease: In this study, we examined clinical blood parameters, serum EV profiles, and EV cargo proteins, including the tetraspanins (CD9 and CD63), as well as the hepatic LD-associated perilipins (PLIN2 and PLIN3), in relation to pathophysiological characteristics of obese and lean MASLD compared with non-MASLD controls.