TARDBP and neuropathy: In a study using skin punch biopsies from 18 ALS patients and 18 controls, Ren Y. et al. found TDP-43 deposition in all samples, while phosphorylated TDP-43 (pTDP-43) was detected in 33.3% of ALS cases and correlated with higher Small-Fiber Neuropathy Symptoms Inventory Questionnaire (SFN-SIQ) scores, implicating small fiber involvement [54].