Table I.

Expression of clock genes in liver, colorectal, gastric and pancreatic cancer.

					Clock gene expression
Author, year	Cancer type	Country	Carcinoma/peritumoral tissue cases, n	Detection method	CLOCK	BMAL1	Per1	Per2	Per3	Cry1	Cry2	CKIε	Tim	(Refs.)
Lin et al, 2008	Liver	Taiwan	46/46	RT-qPCR and IHC	NS	NS	↓	↓	↓	NS	↓	NS	↓	(82)
Yang et al, 2014	Liver	China	30/30	RT-qPCR	NS	NS	↓	↓	↓	NS	↓	NS	ND	(83)
Krugluger, et al 2007	Colorectal	Austria	30/30	RT-qPCR	NS	ND	↓	NS	ND	ND	ND	ND	ND	(84)
Wang et al, 2011	Colorectal	China	38/38	RT-qPCR and IHC	ND	ND	ND	↓	ND	ND	ND	ND	ND	(85)
Mazzoccoli et al, 2011	Colorectal	Italy	19/19	RT-qPCR	NS	ND	↓	↓	↓	NS	↓	NS	↑	(86)
Oshima et al, 2011	Colorectal	Japan	202/202	RT-qPCR	↑	NS	↓	NS	↓	NS	NS	↑	ND	(87)
Wang et al, 2012	Colorectal	China	203/203	RT-qPCR and IHC	ND	ND	ND	ND	↓	ND	ND	ND	ND	(88)
Karantanos et al, 2013	Colorectal	China	30/30	RT-qPCR and IF	↑	ND	ND	ND	ND	ND	ND	ND	ND	(89)
Wang et al, 2013	Colorectal	China	168/10	RT-qPCR and IHC	ND	ND	ND	ND	ND	↑	ND	ND	ND	(90)
Yu et al, 2013	Colorectal	Greece	42/42	RT-qPCR	↑	↑	↓	NS	↓	ND	ND	ND	ND	(91)
Wang et al, 2015	Colorectal	China	203/203	RT-qPCR and IHC	ND	ND	↓	ND	ND	ND	ND	ND	ND	(92)
Zhao et al, 2014	Gastric	China	246/45	IHC	ND	ND	↓	ND	↓	ND	ND	ND	ND	(93)
Hu et al, 2014	Gastric	Taiwan	29/29	RT-qPCR and IHC	NS	NS	NS	↑	NS	NS	NS	NS	NS	(94)
Relles et al, 2013	Pancreatic	USA	65/50	RT-qPCR	NS	NS	↓	↓	↓	NS	↓	↓	NS	(95)

CLOCK, circadian locomotor output cycles kaput; BMAL1, brain and muscle arylhydrocarbon receptor nuclear translocator-like 1; Per, period; Cry, cryptochrome; CKIε, casein kinase Iε; CCG, circadian-clock-controlled gene; Tim, timeless; RT-qPCR, reverse transcription-quantitative polymerase chain reaction; IHC, immunohistochemistry; IF, immunofluorescence; NS, no significant difference between expression in carcinoma and para-carcinoma tissues; ↓, decreased expression in carcinoma tissue; ↑, increased expression in carcinoma tissue; ND, not detected.