COL1A1 and metabolic dysfunction-associated steatohepatitis: Interestingly, as shown in Figure S1A–C, the expression pattern of the GDF15, COL1A1, and COL3A1 genes was also confirmed in a previously published mouse model of MASH, in which the GDF15, COL1A1, and COL3A1 transcript levels were all significantly upregulated in the liver of mice with WD-induced MASH compared to that of ND control mice.