Relative TKR mRNA expression levels in canine normal lung tissue and companion lung cpAC biospecimens from three dogs. (A) Reverse transcriptase TKR cDNA transcripts in normal lung (N) and lung cpAC (T). GAPDH serves as a loading control. (B) Densitometry: the levels of tumor TKR cDNA normalized to total normal lung and GAPDH. Error bars, mean ± SEM. *EGFR and ALK cpAC/normal of three dogs: P < .05.