For SPASTIN (SPAST), a significant decrease at both the N0 and N4 stage of differentiation was reported in SPG4-HSP patient cell lines compared to healthy CTRLs (Figure 4H and quantified in Figure 4I), underlining a significant decrease in SPASTIN availability for hiPSCs and differentiated lower MNs. Here, SPAST is linked to hereditary spastic paraplegia.