Upon formononetin treatment, the activation of STAT3/5 pathway was inhibited in multiple myeloma cells, as evidenced by reduced levels of expression of phosphorylated STAT3 proteins (Tyr705 and Ser727) and p-STAT5 (Tyr694/Tyr699) proteins upon formononetin treatment, but the treatment did not affect the total STAT proteins level. Here, STAT3 is linked to plasma cell myeloma.