Publicly available next-generation sequencing breast cancer datasets (n = 185) 12,15–17,41–43 were interrogated and revealed that BCAS4 is the 5′ partner gene in the validated fusion BCAS4–BCAS3 in MCF7 cells 13,17 and that FAF1 is involved in a DNA rearrangement in an ER-negative/HER2-negative primary breast cancer. Here, BCAS4 is linked to breast cancer.