Table 2:

Major intercellular routes and signaling events in the mechanisms of radiation-induced bystander effects

		Main references
Routes and Pathways	GJIC mediated by Connexin 43	(Azzam, de Toledo et al. 1998, Azzam, de Toledo et al. 2001, Zhou, Suzuki et al. 2001)
	Exosomes	(Al-Mayah, Irons et al. 2012, Jella, Rani et al. 2014)
	TNTs	(Matejka and Reindl 2020)
	DNA damage and repair	(Little, Nagasawa et al. 2003, Nagasawa, Huo et al. 2003)
	Oxidative metabolism	(Narayanan, Goodwin et al. 1997, Azzam, De Toledo et al. 2002)
	Double stranded DNA (cGAS/Sting pathway)	(Jesenko, Bosnjak et al. 2020)
Signals/Molecules Transmitted to Bystander Cells	Soluble factors cocktail secreted in medium	(Mothersill and Seymour 1997, Iyer, Lehnert et al. 2000, Desai, Kumar et al. 2013)
	Cox 2	(Zhou, Ivanov et al. 2005)
	Rad 9	(Zhu, Zhou et al. 2005)
	TGF-β	(Hu, Xu et al. 2014)
	TNF-α and serum amyloid albumin	(Song, Hu et al. 2021)
	IL-6 and IL-8	(Mariotti, Bertolotti et al. 2012)
	Nitric oxide and superoxide	(Shao, Stewart et al. 2003)
	Prostaglandin-2 (PGE-2)	(Ivanov, Zhou et al. 2010)
	HMGB1	(Zhu, Hu et al. 2021)
	Ions/small molecule transmission by GJIC	(Meşe, Richard et al. 2007)
	Circulating miRNAs	(Xu, Wang et al. 2015)
	ATP	(Burdak-Rothkamm, Rothkamm et al. 2008, Mancuso, Pasquali et al. 2011, Ohshima, Tsukimoto et al. 2012)