Using bulk RNA-seq, numerous novel gene fusions have been identified and utilized as diagnostic or prognostic markers and therapeutic targets in tumors, such as the NUP98-PHF23 fusion gene in acute myeloid leukemia (AML), as well as recurrent or pathogenic fusion genes like ESR1-CCDC170, SEC16A-NOTCH1, SEC22B-NOTCH2, and ESR1-YAP1 in breast cancer 69-71. The gene discussed is ESR1; the disease is acute myeloid leukemia.