TRIM21 and metabolic dysfunction-associated steatohepatitis: Knockdown of A1CF using GalNAc-siA1cf in 20-week-old mice that were fed a NASH diet induced a similar reduction in KHK-C and GK isoforms than overexpression of TRIM21, due to splicing defects caused by A1CF depletion (Figure 5C and Supplemental Figure 5A).