Here, we identified on a genome-wide level, the sets of AS events and splicing factors regulated at the RNA level in this breast cancer cell model of acquired resistance to doxorubicin, and identified through an siRNA screen two little studied splicing factors (ZRANB2 and SYF2), whose depletion reduced Doxo resistance and subsets of resistance-associated AS events. The gene discussed is SYF2; the disease is breast cancer.