As shown in Fig. 1B (top), the supernatants from MYCN-nonamplified neuroblastoma were highly chemoattractive for monocytes, MDC and PDC, with more than 10%, 18%, and 7% of migrating cells respectively (in 2 hours), compared with the supernatants from MYCN-amplified neuroblastoma that did not induce any significant migration. The gene discussed is PDC; the disease is neuroblastoma.