SOAT1 and Behcet disease: IL-6 induced stimulation and proliferation of cells requires signal transduction mediated by the STAT (Signal Transducers and activators of transcription) (STAT1 and STAT3) and MAPK (mitogen-activated protein kinase) pathways.19 In inflammation, a positive feedback auto-crine loop exists in fibroblasts with upregulated STAT4 leading to sustained IL-6 transcription.20 Whether fibro-blasts are involved in BD or MGUS pathogenesis remains to be determined.