From the perspective of function, we propose that ZNF121 likely plays a role in tumor angiogenesis because of the increase in ANG1 protein in the medium of T‐47D cells with the knockdown of ZNF121. Considering that ZNF121 is overexpressed in breast cancer and knockdown of ZNF121 inhibits cell proliferation 6, it seems somewhat surprising that knockdown of ZNF121 also increased the expression of ANG1, an angiogenesis modulator. This evidence concerns the gene ANGPT1 and breast cancer.