Abstract β-Amyloid precursor protein (APP) belongs to a family of homologous β-amyloid precursor-like proteins (APLPs) including APLP1 and APLP2. Previously it has been shown that APP is subject to regulation by retinoic acid (RA). In this paper we show that APLP1 and APLP2 mRNA expression is upregulated during RA-induced differentiation of human SH-SY5Y neuroblastoma cells. The cells were treated with RA (10 μM) for 3 and 6 days and mRNA levels were analysed by a non-radioactive Northern blot assay. RA induced a 2- to 3-fold increase in the gene expression of both APLP2 and APP, whereas the increase in APLP1 mRNA expression was significantly higher. Our results support a role for APLPs during neuronal differentiation.