A remarkable splicing change in the polymerase delta interacting protein 3 (POLDIP3) as a result of TAR DNA binding protein (TDP-43) depletion in two types of cultured cells POLDIP3 (variant-1) decreased and POLDIP3 lacking exon 3 (variant-2) increased in cells treated with TDP-43 siRNA. POLDIP3 variant-2 mRNA was found to be increased in motor cortex, spinal cord, and spinal motor neurons collected by laser capture microdissection in patients with ALS. The gene discussed is TARDBP; the disease is amyotrophic lateral sclerosis.