Expression of full-length ATIC-ALK cDNA in mouse fibroblasts revealed that the fusion protein (a) possesses constitutive tyrosine kinase activity; (b) forms stable complexes with the signaling proteins Grb2 and Shc; (c) induces tyrosine-phosphorylation of Shc; and (d) provokes oncogenic transformation.    ///    Nucleotide sequence analysis of ALK transcripts isolated by 5'-rapid amplification of cDNA ends revealed a chimeric mRNA corresponding to an ATIC-ALK in-frame fusion.