OPTN and amyotrophic lateral sclerosis: Prtenjaca et al. (2022) used CRISPR/Cas9 methodology to create OPTN knockout (KO) cell lines for Neuro 2a and NSC-34 neurons and BV2 microglia to investigate the relationship between optineurin and TDP-43. Their research showed that OPTN mutations might lead to elevated levels of TDP-43 protein in microglia when optineurin is absent (Prtenjaca et al., 2022). In addition, Zhang et al. (2022) created a heterozygous FUS-Q290X knock in the human embryonic stem cell (hESC) line, which will be a valuable tool for investigating the disease mechanisms of ALS using the CRISPR/Cas9 system.