Total RNA was isolated from human B cell lines (Daudi, Raji, TEM), human neuronal cell lines (SK-N, HCN-1A) and mouse lung tissue using TRIzol reagent. Five micrograms of total RNA from human tissues (brain, heart, skeletal muscle, colon, liver, thymus, kidney, intestine, lung, placenta and spleen), or human B cell lines (Daudi, Raji, TEM) and human neuronal cell lines (SK-N, HCN-1A), or mouse lung tissue was treated with DNase I and reverse transcribed in the presence of 250 ng of Random Primers, 1Â PCR Buffer, 10 mM dNTPs and 200 U of SuperScript II reverse transcriptase (RT; Invitrogen) in a final reaction volume of 20 ml. Reactions were carried out at 25 C for 10 min, 42 C for 50 min, followed by a 15-min step at 70 C to denature the enzyme.