MAPK8 and proximal spinal muscular atrophy: Moreover, given that SMA can be considered as a multi-systemic disease (Shababi et al., 2014; Simone et al., 2016), we can hypothesize that the inhibition of all the JNK isoforms could exert protective effects also in other body district affected in SMA pathology, such as the heart (Bevan et al., 2010; Heier et al., 2010), the diaphragm (Supinski et al., 2009) and other skeletal muscles (Anderson et al., 2003), in which it has been shown that this family protein is expressed.