Although previous immunoblot analyses have reported slight differences in the molecular species of sarkosyl-insoluble phosphorylated TDP-43 in FTLD-TDP type A and B cases, all of the FTLD-TDP type B cases included in that comparison had co-existing ALS, raising the question as to whether the removal of FTLD-ALS cases from that experiment and the current FTLD classification scheme would augment the broad pathological and molecular overlap currently already seen between FTLD-TDP type A and B cases [5, 32]. This evidence concerns the gene TARDBP and amyotrophic lateral sclerosis.