BACE1 and neuroblastoma: However, BACE1 and PSEN1 (which respectively encode for the active sites of the β- and γ-secretases) transcript levels decreased to approximately 0.6-fold in neuroblastoma cells treated with either MK4 or MK7R with respect to control (Figure 2b,c; F = 5.09, p < 0.05 MK4 vs. ctrl; F = 5.4, p < 0.01 MK7R vs. ctrl).