In a mouse model of arsenite-induced hepatic fibrosis, miRNA-21 disrupts the metabolic reprogramming of CD4 T cells through the PTEN/PI3K/AKT pathway to promote polarisation towards a Th2 phenotype, upregulating pro-fibrotic factors such as the transcription factors GATA binding protein 3 (GATA3), and pro-fibrotic factors like IL-4 and IL-13, thus promoting the activation of HSCs (Sun et al., 2022). The gene discussed is IL4; the disease is Hepatic fibrosis.