ZCCHC2 and amyotrophic lateral sclerosis: For the downregulated circRNAs, 6 out of 10 circRNAs in ALS muscle biopsies, hsa_circ_0047886, hsa_circ_0141401, hsa_circ_0117010, hsa_circ_0000033, hsa_circ_0000247, and hsa_circ_0009027, were selectively reduced while the linear counterparts (ZCCHC2, ALPK2, NPHP1, CEP85, MCU, and ZNF362 mRNAs, respectively) were not.