Electrophoretic mobility shift assays (EMSA) conducted with nuclear extracts from HK-2 cells have identified SP1 and multiple SP3 isoforms, whose co-mutation suppresses the gene transcription of macrophage, which can mediate the progression of renal fibrosis (Hughes et al., 2002; Li, Fu & Liu, 2022). Here, SP3 is linked to renal fibrosis.