Microarray and proteomic expression patterns in response to cadmium exposure were analyzed in human lung epithelial cells. Among 35,000 genes analyzed by cDNA microarray, 228 genes were up-regulated and 99 genes were down-regulated, based on a fold change cut-off value of ${geq}2$. Combining two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization-time-of-flight-mass spectrometry (MALDI-ToF-MS), 25 of 629 protein spots showed fold changes in expression ${geq}2$ (17 up-regulated, 8 down-regulated). After comparing the cDNA microarray and proteomic analyses, only transglutaminase 2, translation elongation factor 1 alpha 1, and glyceraldehyde-3-phosphate dehydrogenase showed overlapping signals in the cDNA microarray and proteomic analyses, whereas the remaining differentially expressed proteins showed large discrepancies with respect to mRNA expression.