ACVR1C and plasma cell myeloma: Our study introduces several novels secDrugs as potential synergistic partners of PIs that have never been studied as potent single-agent or combination therapy options in myeloma model systems, including KIN001-102 (A6730; Akt1/2 kinase inhibitor) and SB505124 (inhibitor of transforming growth factor-β type I receptor or ALK4, ALK7 that activates the SMAD2/3 pathway).