STAT3 and plasma cell myeloma: Incubation of U266-B1 cells with Atiprimod at concentrations ranging from 1 to 8 μM for 1 h significantly downregulated STAT3 phosphorylation (Figure 2A, lower panel), suggesting that Atiprimod inhibits the Janus tyrosine kinase (JAK)-STAT signalling pathway in myeloma cells.