Transcriptional profiles of HS-27a cells in response to HS-5 CM or IL-1β. RNA isolated from untreated HS-27a cells or cells treated with 1× HS-5 CM or 2 ng/mL IL-1β for 4 days was hybridized to an oligonucleotide array chip that quantitatively monitors the expression of 250 genes of interest in hematopoiesis and immunology. Genes showing a detectable expression level are plotted. Dots represent expression level in the untreated cells, and a line is drawn to the expression level after cell treatment. Dots without lines represent genes whose expression level did not change in response to cell treatment. Lines in bold indicate genes whose expression levels significantly increased (lines to the right of the dots) or decreased (lines to the left of the dots) as determined by an algorithm that makes a call based on several statistical criteria.35 In addition to the genes plotted, MIP-1, CD44, SAA, LMP2, and LMP7B were only detected after IL-1β treatment and N-CADHERIN and ICAM-1 were detected only after treatment with HS-5 CM.