Interestingly, CCL2 was secreted at high level by the MYCN-nonamplified AS (mean = 2,329 pg/mL) and SH (mean = 5,503 pg/mL) neuroblastoma cell lines, but was not found in the supernatants of MYCN-amplified neuroblastoma cell lines (N91 and DZ), suggesting that this chemokine could be involved in the differential recruitment of monocytes and DC we observed. This evidence concerns the gene MYCN and neuroblastoma.