ACTB and lung adenocarcinoma: To confirm the in silico results, we performed RNA immunoprecipitation (RIP) assays with an MSI2 antibody pulldown coupled with RT-qPCR in three lung adenocarcinoma cell lines: A549 (Supplementary Figure S2A), Hcc1171, and H441 (Figure 1D), using the previously defined MSI2 target mRNAs (PTP4A, TGFβR1, SMAD3) [25,38] as positive controls and ACTB and GAPDH as negative controls.