Phase-contrast micrographs of breast cancer primary cells (BCpc) at different stages of the culture. A. Initial phase of cell spreading from the tissue after 7 days in culture (10x). B. 15-day culture showing the cells fully dissociated (20x). C. A detail of the culture at the 4th growth passage showing the stellate morphology and cellular protrusions (spikes) (20x). D. The cells forming multilayered foci within 24-48 hrs in culture (10x). Calibration bars: 30 μm.