CD38 and metabolic dysfunction-associated steatotic liver disease: Histological analysis also revealed that steatosis (score 0–3), hepatocyte ballooning (score 0–2), and lobular inflammation (score 0–3), as estimated by the nonalcoholic fatty liver disease activity score (NAS) (Kleiner et al. 2005), were alleviated in CD38 vaccine mice relative to KLH mice (Figure 5J,K).