POU2AF3 and small cell lung carcinoma: Concurrent with the loss of chromatin accessibility, chromatinimmunoprecipitation followed by sequencing (ChIP-seq) showed diminishedchromatin binding of POU2F3 and its coactivators (POU2AF2 and POU2AF3) at theAU-15330-mediated loss sites, as examined by tagging endogenous or exogenousPOU2F3 and its coactivators in SCLC-P cell lines (Figures 2C and S2G–S2M).