NCALD and proximal spinal muscular atrophy: Through a combination of experiments in human tissues and cell lines, as well as in mouse and zebrafish models of SMA, Wirth's group has identified both plastin 3 (PLS3) and neurocalcin delta (NCALD) as protective modifiers in SMA-affected individuals (Ackermann et al., 2013; Heesen et al., 2016; Oprea et al., 2008; Riessland et al., 2017).