Metabolic dysfunction-associated steatotic liver disease (MASLD) and metabolic dysfunction-associated steatohepatitis (MASH) are major health burdens. Appropriate in vitro models are necessary to study these diseases and to understand the molecules and mechanisms involved. Most in vitro models are based on tumour cells. In this research we have used CRISPR/Cas9 prime editing to introduce the PNPLA3 p.I148M gene variant into a healthy-derived immortalised human hepatocyte (IHH) cell line to generate a new in vitro model of MASLD to help understand stetatotic liver disease.