To establish a HIF-cell-tracing method (HIF-MARCer) amenable for in vivo hypoxia imaging, H1299 non-small cell lung carcinoma cells were transduced with HIF-1α-eGFP-CreERT2 complementary DNA (cDNA) (MARCer fusion protein) expression vector and with a loxP-flanked STOP tdTomato cassette (H1299-MR cells; Fig. 1A). This evidence concerns the gene HIF1A and non-small cell lung carcinoma.