To investigate whether the modulation of PTX3 expression might impact the stem-like behavior/population in low and high-grade BC, a sphere-forming assay was performed on PTX3 modulated RT4-shPTX3, 5637-hPTX3, and HT1376-hPTX3 cells and on their corresponding controls (RT4-shNT, 5637-Mock, and HT1376-Mock cells, respectively). Here, PTX3 is linked to breast cancer.