To assess which AU-rich element binding proteins (AUBPs) could mediate regulation of PD-L1 expression downstream of RAS signaling, we performed a selected siRNA screen of likely candidate genes, AUF1, KSRP, HuR, and TTP (also known as tristetraprolin or ZFP36), in three RAS mutant lung cancer cell lines (Figures 3A–3C). The gene discussed is KHSRP; the disease is lung carcinoma.