In breast cancer cells, binding of lncRNA MACC1‐AS1 to PTBP1 reduces its own degradation and increases its sponge effect on multiple oncogenic miRNAs (miR‐145‐3p, miR‐384, or miR‐342‐5p) to promote cell proliferation and breast tumour progression. This evidence concerns the gene PTBP1 and breast carcinoma.