ALCAM and non-small cell lung carcinoma: Our finding that CD166/ALCAM expression is increased in non-irradiated A549 and H460 lung sphere cells and even more dramatically upregulated in radiation survived sphere cells of the A549 cell line suggests that CD166/ALCAM might serve as a marker for the detection of CSCs and radioresistant counterparts within NSCLC tumors and bears the potential to predict the outcome of radiotherapy by assessment of CSC density.