We showed that all ASOs targeting PKHD1′s Exon 21, to a great extent, restore the expression of the normal transcript in cells, indicating that these ASOs might be promising therapeutic agents in the treatment of ARPKD caused by Exon 21 splicing mutations of the PKHD1 gene. This evidence concerns the gene PKHD1 and autosomal recessive polycystic kidney disease.