S3.

Heat shock promotes tumor-initiating cell traits. (A, B) Phase-contrast pictures of tumor spheres formed by pre-heat shock treated SW620 cells, grown in serum-free sphere medium on Ultra-low attachment surface plates. Whole view of sphere assay was showed in panel A, representative magnified view was showed in B. scale bar, 50 μm. (C) Quantification of tumor spheres formed by SW620 cells. The mean number of spheres per 5000 cells and the mean diameter of spheres are calculated in triplicate samples, *P < 0.05, ** P < 0.01. (D) Representative images of matrigel pre-coated transwell assays with CT-26 and SW620 cells.