Table 2.

Gene categorization/grouping on the basis of functional categories after the evaluation of CTCs

Functional categories	Associated genes
Epithelial phenotype	KRT8 (Powell et al., 2012; Ting et al., 2014), KRT18 (Powell et al., 2012; Ting et al., 2014), KRT19 (Powell et al., 2012; Smirnov et al., 2005; Ting et al., 2014), CTNNB1 (Powell et al., 2012), Krt7 (Ting et al., 2014), Epcam (Lu et al., 2010; Smirnov et al., 2005; Sun et al., 2013; Ting et al., 2014), EGFR (Chen, C.L. et al., 2013; Kallergi et al., 2008; Lu et al., 2010; Ting et al., 2014), CDH1 (Armstrong et al., 2011; Ting et al., 2014), MUC1(Lu et al., 2010; Pierga et al., 2007; Zhu et al., 2014), HER2 (Kolostova et al., 2015b), ERBB2 (Kolostova et al., 2015b; Lu et al., 2010)
Epithelial mesenchymal transition (EMT)	TGFβ1(Powell et al., 2012), FOXC1 (Powell et al., 2012), CXCR4, (Powell et al., 2012), NFKB1(Powell et al., 2012), VIM (Armstrong et al., 2011; Lu et al., 2010; Powell et al., 2012; Ting et al., 2014), ZEB2 (Powell et al., 2012), CDH11 (Ting et al., 2014), PTPRN2 (Chen, C.L. et al., 2013), ALDH1 (Chen, C.L. et al., 2013), ESR2 (Chen, C.L. et al., 2013), WNT5A (Chen, C.L. et al., 2013), Twist1 (Aktas et al., 2009; Giordano et al., 2012; Lu et al., 2010), Akt2 (Giordano et al., 2012; Kolostova et al., 2015b), PI3Kα (Aktas et al., 2009; Kolostova et al., 2015b), SNAIL1 (Giordano et al., 2012), ZEB1 (Giordano et al., 2012), TG2 (Giordano et al., 2012)
Metastasis	S100A4 (Powell et al., 2012), S100A9 (Powell et al., 2012), S100A14 (Smirnov et al., 2005), S100A16 (Smirnov et al., 2005), NPTN (Powell et al., 2012), KLK3 (Smirnov et al., 2005), CEACAM5 (Smirnov et al., 2005), KRT 20 (Smirnov et al., 2005), FABP1 (Smirnov et al., 2005)
PI3K/AKT/mTOR pathway	AKT1, AKT2, PIK3R1, PTEN (Powell et al., 2012)
Apoptosis	BAX, CASP3, CD53, CD59 (Powell et al., 2012)
Stem cell phenotype	CD24 (Giordano et al., 2012; Lu et al., 2010; Powell et al., 2012), CD44 (Giordano et al., 2012; Lu et al., 2010; Powell et al., 2012), CD133 (Armstrong et al., 2011; Giordano et al., 2012; Sun et al., 2013), ALDH1 (Aktas et al., 2009; Giordano et al., 2012; Kolostova et al., 2015b)
DNA repair	PARP1 (Powell et al., 2012)
Cell metabolism	SLC2A1, TFRC (Powell et al., 2012)
Cell proliferation	RRM1, MAPK14 (Powell et al., 2012)