ABCG2 and neuroblastoma: As an example, we present the LSCM evaluation of the polymer conjugate intracellular accumulation, which was conducted in a study focusing on overcoming multi-drug resistance (MDR) based on ATP Binding Cassette (ABC) transporters using amphiphilic diblock polymer nanotherapeutics bearing Dox (attached by a biodegradable spacer to the polymer carrier) in Dox-resistant human neuroblastoma cell lines overexpressing ABC transporters.