MYCN and neuroblastoma: The above data indicate that MYCN-amplified NB cells are not responsive to EGF, while SH-SY5Y cells (MYCN-not-amplified) proliferate at a higher rate, and yet, their proliferation rate increases (the Dt was reduced by 25%) when CD is reduced by EGF or inhibited by PstA We investigated further the impact of CD on the growth of MYCN-not-amplified SH-SY5Y NB cells grown in adherent (2D) and non-adherent (3D) conditions.