Fig. 5: Characterization of rs78740585.

a Heat map showing the expression of the SMARCD gene family in blood cells. Notably, expression of SMARCD3 in plasma cells is normally very low; the MM risk allele upregulates SMARCD3 in this cell type (Supplementary Table 2). The color scale is log₂-transformed, median-centered RNA-seq data²³. b Motif analysis predicted that the SMARCD3 high-expressing rs78740585-A allele creates a binding site for IRF4. Arrow indicates the altered recognition base. c Electromobility shift assay showing selective binding of IRF4 to rs78740585-A probe. Arrow indicates supershift with an antibody towards IRF4. d siRNA-knockdown of IRF4 reduced luciferase activity for rs78740585-A relative to rs78740585-G in L363 cells. The y-axis indicates the log₂ ratio of the luciferase/renilla signal for rs78740585-A relative to the rs78740585-G construct. The bottom, middle, and top of each box plot represent the 25th, 50th, and 75th percentiles. The whiskers represent the non-outlier minimum and maximum values, located at 1.5 times the interquartile range from the bottom and top of the box, respectively. The P value is for the two-sided Student’s t-test. e Western blot confirming knockdown. LP labeled probe, NE L363 nuclear extract, ULP unlabeled probe, α-IRF4 antibody against IRF4.