CD44 and breast cancer: qRT‐PCR was used to detect the expression of miR‐200c in CD44+CD24− phenotype BCSCs and the remaining non‐CD44+CD24− phenotype breast cancer cells that were sorted by flow cytometry (SKBR3‐S/SKBR3‐nS, MCF‐7‐S/MCF‐7‐nS), suspension microspheres and the remaining cells after filtration of the microspheres that only serum‐free suspension cultured and not sorted by flow cytometry (SKBR3‐SM/SKBR3‐nSM, MCF‐7‐SM/MCF‐7‐nSM), normal adherent cells of SKBR3 and MCF‐7.