2-DE analysis of NB cells treated or not with ATRA.

<p>Representative image from three independent experiments of coomassie-stained 2-DE patterns of NB cell line SJ-N-KP: (<b>A</b>) 24 h control cells; (<b>B</b>) 24 h ATRA treatment; (<b>C</b>) 9 days control cells; (<b>D</b>) 9 days ATRA treatment. Proteins were separated using 17-cm, pH-4–7 strips followed by SDSPAGE on 10%, 18×20-cm gels. Proteins showing apparent differential expression were identified by progressive numbers on the <i>black squares</i>. Corresponding identifications are reported in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0018254#pone-0018254-t001" target="_blank">Table 1</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0018254#pone-0018254-t002" target="_blank">2</a>.