High Mobility Group A1 (HMGA1) and ribosomal protein S6 kinase alpha-3 (RSK2) regulate a common set of genes. Gene expression analyses performed by qRT-PCR on MDA-MB-231 cells transfected with (A) control (siCTRL) or HMGA1–targeting (siA1_3) small interfering RNAs, (B) control (siCTRL) or RSK2–targeting (siRSK2) siRNA, or (C) treated for 24 h with BI–D1870 10 μM or dimethyl sulfoxide (CTRL) as a control. siRNA-treated cells were harvested after 72 h. Expression of the HMGA1 subset signature (Hsss - AURKB, KIF23, KIF4A, CENPF), RSK2, and HMGA1 genes was analysed using glyceraldehydes-3-phosphate dehydrogenase (GAPDH) or cyclophilin-33 (CYP33) as internal reference genes. Data are represented as relative gene expression values with respect to control samples. Standard deviations (n = 3) and statistical significance (t-test) are indicated (p-values: *: p < 0.05; **: p < 0.01; ***: p < 0.001).