After stimulation with SCGB3A2, the SDC1 signal became relatively concentrated on cell protrusions equivalent to the uropod structure of myeloma (Børset et al., 2000; Yang et al., 2003), which co-localized with SCGB3A2 (Figure 4A,+SCGB3A2). Here, SCGB3A2 is linked to plasma cell myeloma.