[Isoform 1]: Nucleus . Actively transported through the nuclear pore complex (NPC). .; [Isoform 2]: Nucleus .
Isoform 1: Does not seem to be expressed in normal muscle, but is detected in muscle of individuals with FSHD, and also in testis (at protein level) (PubMed:21060811, PubMed:17984056). Isoform 1: Does not seem to be expressed in normal muscle, but in muscle of individuals with FSHD, where it may be toxic to cells (PubMed:21060811, PubMed:17984056). Isoform 2: Detected in skeletal muscle, fibroblasts and testis from healthy individuals (PubMed:21060811).