Induction of anchorage-independent growth by SW620 and CRC-MF conditioned media was dependent on CXCL1. a Neutralizing antibodies to CXCL1, in comparison to irrelevant isotype-specific control IgG Ab, inhibited the anchorage independent growth of non-transformed NIH3T3 cells induced by serum-free SW620 and serum-containing CRC-MF conditioned media. b Neutralizing antibodies to CXCL1 inhibited the anchorage independent growth of malignant SW620 cells in comparison to irrelevant isotype-specific control IgG Ab. c, d SW620 cells stably expressing two different CXCL1 specific shRNAs secreted lower CXCL1 levels (c) and had suppressed soft agar growth (d) in comparison to control shRNA. p values were as indicated: *p < 0.05, **p < 0.01, ***p < 0.001.