Top networks associated with U251 tumor human genes increased by metronomic CPA treatment on both day 12 and day 18 (late responses), as determined by IPA. A) Top network for the human chemokine CXCL10, involved in innate immune activation via toll-like receptor (TLR) and interferon (IFN) response pathways. B) Top network for the human chemokine CXCL11, involved in innate immune activation via DNA damage, TLR, IFN, and secretory chemokine/cytokine pathways. C) Top network for the human chemokine CXCL9, involved in innate immune activation via toll-like receptor, interleukin, and cell stress ligand MICB response pathways. Deeper shades of red-filled shapes indicate stronger up regulation of the gene by metronomic CPA treatment, as determined by microarray analysis. Solid arrows: protein-DNA interactions; solid lines: protein-protein; dashed arrows: regulation of gene expression; colored: related to highlighted factor(s). Shapes indicate protein family: rectangle: receptor; square: cytokine; triangle: kinase; diamond: enzyme; oval: factor (ie., transcription); concentric circles: complex; circle: other.