Table 4.

Comparison between current study and the recent in-vitro studies carried out on RS prediction by gene expression

Reference	Cell Type	Method	Gene(s) Investigated	Conclusion
Hernandez LAH et al. (40)	*PBMCs of BC patients	Microarray	Microarray probe	Significant associations between the gene expression profile and the development of acute and late toxicity in consecutive, unselected patients
Mayer et al. (41)	*PBMCs from head and neck and BC patients	Microarray	Microarray probe	A set of 67 radiation-induced genes was potentially capable to differentiate between radiosensitive and normal reacting patients
Torres-Roca et al. (42)	cancer cell lines of numerous types	real-time PCR	RbAp48, RGS19 R5PIA	Gene expression profile could be used to predict SF2** as a dose response and RS index
Lu X-X et al. (43)	EC9706 esophageal cancer cells	real-time PCR	Cox-2 MMP2 Bcl-2 Bax	Downregulation of Cox-2, MMP2 and Bcl-2 expression followed by upregulation of Bax expression, are associated with increased RS
Mohammadi M et al. (44)	TE1, TE8 and TE11 esophageal cancer cell lines	real-time PCR	Hdm2 P53	Regulation of Hdm2 and P53 gene expression could distinguished radiosensitive compared to radioresistance cell lines that may occur due to apoptosis
Badie C et al. (45)	*PBMCs of BC patients	real-time PCR	CDKN1A, GADD45A, CCNB1, and BBC3	Post-irradiation expression response was significantly reduced for CDKN1A in severe reactors compared to normal
Wei et al. (46)	Peripheral blood plasma	real-time PCR	miR-145	Plasma miR-145 is reduced in cervical cancer and is a novel candidate biomarker for diagnosing CC and predicting RS
Current study	*PBMCs of BC patients	real-time PCR	Bax Bcl-2 Bax/Bcl-2 ratio	Significant correlations between Bax/Bcl-2 ratio determined before RT and clinical can be used as a potential test to identify radiosensitive individuals

^*Peripheral blood mononuclear cells

^**SF2=survival fraction at 2 Gy