Matching image analysis for 2-DE. This image represents 4 nontreated 2-DE gels compared with 4 ATRA-treated 2-DE gels. The pH range was 4 to 7, with molecular weight, isoelectric point (pI) grinds, and histograms representing the quantification of identified proteins within the gels. The first 4 bars in each histogram represent the relative intensity of a protein spot from 4 individual 2-DE gels during nontreatment, and the last 4 bars represent the relative intensity of the same protein spot from 4 individual 2-DE gels during ATRA treatment. Proteins down-regulated by means of ATRA treatment are displayed as red ellipses, and up-regulated proteins are displayed as blue ellipses. Proteins labeled with “U” or “D” are listed in Table 1 along with their degree of regulation as a function of ATRA treatment. (B) A 2-DE raw image (original magnification, × 1) for nontreated and ATRA-treated 2-DE gels corresponding to the gel region where phosphoglycerate mutase 1 resolves (circle).