TARDBP and amyotrophic lateral sclerosis: Based on the morphology and distribution of cortical TDP-43 pathology, FTLD cases are routinely classified into one of four pathological subtypes (FTLD-TDP Type A-D) [21, 27], with Types A and B the most commonly identified in the ~20% of FTLD cases with ALS (FTLD-ALS) [8, 17, 22, 27].