Figure 3

Histomorphological changesin tumor cells after conversion to wild-type EGFR . (A) Tumor cells formed a glandular configuration when they harbored the L858R EGFR mutation. (B) Tumor cells were clustered in a compact solid pattern after they converted to wild-type EGFR-expressing cells. These tumor cells strongly expressed TTF-1, confirming that it is still adenocarcinoma.