ALK and neuroblastoma: When the levels of phosphorylated ALK in the neuroblastoma cell lines were normalized to total ALK signals from the immunoassays and compared with densitometry of the immunoblots, there was a positive correlation that was statistically significant for the total ALK and pY1278 and pY1586 ALK assays, and although not significant, a positive trend between densitometry and immunoassay for the detection of pY1604 ALK was seen (Fig. 2C).