Screening assays and methods of using same for screening to identify modulator agents or compounds that target endoplasmic reticulum stress related signaling pathways to induce apoptosis are described herein. Pharmaceutical compositions comprising modulator agents or compounds identified by screening assays described herein are also encompassed. Methods for treating a myeloproliferative disorder characterized by monoclonal plasma cell proliferation in a subject using the aforementioned modulator agents or compounds are also envisioned. Modulator agents or compounds thereof for use in treating a myeloproliferative disorder in a subject and use of modulator agents or compounds thereof in the preparation of medicaments for the treatment of a myeloproliferative disorder are also encompassed herein. Exemplary myeloproliferative disorders include: monoclonal gammopathy of undetermined significance (MGUS), smoldering multiple myeloma (SMM), and multiple myeloma (MM).
