KIT and neoplasm: Despite the fact that KIT+ NSCLC tumors have an increased prevalence, and increased expression of CD117, as well as an increased proportion of cycling/aneuploid cells, detailed subset analysis of the stem/progenitor markers CD44, CD90 and CD133 on CD117+/cytokeratin+ tumor cells revealed no differences between the tumor cells and CD117+ normal lung stem cells (Figure 2).