In strong support of our hypothesis, analysis of public microarray data sets for Wnt7a expression revealed that: (1) Wnt7a is predominantly expressed in epithelial cells (GEO profiles, GDS1402/NM_004625.1_PROBE1/WNT7A), and (2) there is a profound loss of Wnt7a expression in several human lung cancer studies (Figure 1m). This evidence concerns the gene WNT7A and lung cancer.