At 60 minutes, total TrkA (110kDa plus 140kDa) levels had reduced to 13.4±1.2% in ER membranes (fractions 5 and 6; versus 15 minutes P < 0.0001, n = 6) and increased to 69±6.4% in GN membranes (Fractions 1 and 2; versus 15 minutes P < 0.0001, n = 6), indicating rapid 110kDa TrkA movement from ER to GN, in association with 140kDa TrkA maturation. This evidence concerns the gene NTRK1 and ganglioneuroma.