CCL2 and neuroblastoma: 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.