ATF4 and Miyoshi myopathy: The importance of these observations is supported by studies that have shown the induction of Activating Transcription Factor 4 (ATF4) and of the C/EBP Homologous Protein (CHOP) in MM requires mTORC1 regulation of c‐myelocytomatosis oncogene product (c‐MYC), and that this signaling pathway is a major determinant in the ability of bortezomib to induce apoptosis [15].