RT‐PCR detection of budding RTP gene‐expressions in PDX model post two times 8 Gy irradiation revealed that most RTP gene levels (CST3, CDC37, IGFBP6, ISYNA1, RN7SL2) increased on day 9 when RTP cells were significantly enriched and partial fell back on day 82 when tumor repopulated (Figure 7E). This evidence concerns the gene IGFBP6 and neoplasm.