Fig. 4: Distribution of breast cancer stem cells expressing both PKD-1 and CD36.

a Immunofluorescence microscopy showed that PKD-1⁺ or CD36⁺ cancer stem-like cells (CD44⁺ BCSCs) were located within the blood vessel (white arrows) or tumor nest (pink arrow). H&E staining as a control for tissue structure, and a tumor cell existed within the blood vessel and tumor nest exists in the tumor microenvironment (black arrows). Scale bar = 25 µm or 10 µm. b Immunofluorescence microscopy showed that cancer stem-like cells with positive PKD-1 or CD36 expression were located nearby the tumor blood vessels (white arrow). H&E staining showed tissue structure of the breast cancer and tumor nest was indicated by a black arrow. Scale bar = 25 or 10 µm. c A small subset of CSCs expressing moderate levels of PKD-1 but high levels of CD36 were located outside of cancer nest that also expressed high levels of PKD-1 but moderate levels of CD44 in human BC. A small subset of CSCs expressed moderate levels of PKD-1 and CD44 but minimal levels of CD36 and appeared to form a vessel-like structures. A tumor nest showed strong PKD-1 expression (white arrows). H&E staining as a control for tissue structure. Scale bar = 25 or 10 µm.