Through an analysis of MYST4 gene knockdown in cancer cell lines in multiple organs, including the A2780 ovarian cancer cell line, Skbr3 breast cancer cell line, and Huh7 hepatoma cell line, we found significant reductions in MALAT1 levels in the three MYST4-knockdown tumor cell lines compared to their respective parental cells (Figure 1A; * p < 0.05, ** p < 0.01, and *** p < 0.001; Figure S1). This evidence concerns the gene KAT6B and breast cancer.