JAG1 and Miyoshi myopathy: Additionally, knockdown of Jagged1/2 in MM has been shown to downregulate autocrine and BMSC expression of interleukin-6 (IL-6)—a canonical growth factor for plasma cells that is normally secreted by CD4+ cells and BMSCs (Colombo et al., 2016; Harmer, Falank & Reagan, 2019).