PLS3 and proximal spinal muscular atrophy: Accordingly, in SMN1-deleted asymptomatic women of spinal muscular atrophy (SMA) discordant families, the PLS3 expression is elevated in blood and Epstein–Barr Virus transformed lymphoblastoid cells but not in their SMA-affected siblings, indicating a sex-specific protective effect (see more details in Sect. 3.6.1) [5].