*3.5. Clonogenic Assay*

Human CRC cell lines were seeded at 1 × 10<sup>3</sup> cell/well onto six-well plates. After cells had completely attached, they were treated with 1 or 4 μg/mL of PN, and 10 days later, fixed with 4% paraformaldehyde for 10 min, dried, and stained with 0.05% crystal violet (Sigma) for 15 min. The experiments were performed in triplicate.
