REAGENT or RESOURCE	SOURCE	IDENTIFIER
Biological samples
Human saliva DNA	Biological repository of the NPC Genes, Environment, and EBV (NPCGEE) study (Ye et al.40)	https://doi.org/10.18632/oncotarget.19692
Deposited data
Human genotype data	This paper	National Genomics Data Center (NGDC: GVM000648, https://bigd.big.ac.cn/gvm/getProjectDetail?Project=GVM000648)
EBV genotype data	This paper	National Genomics Data Center (NGDC: GVM000647, https://bigd.big.ac.cn/gvm/getProjectDetail?Project=GVM000647)
Software and algorithms
SAS code: interaction effects	A tutorial on interaction (VanderWeele et al.10); Recommendations for presenting analyses of effect modification and interaction (Knol et al.41)	https://www.hsph.harvard.edu/tyler-vanderweele/tools-and-tutorials/; https://doi.org/10.1093/ije/dyr218
SAS macro: direct and indirect effect	Mediation analysis allowing for exposure–mediator interactions and causal interpretation: Theoretical assumptions and implementation with SAS and SPSS macros (Valeri et at.11)	https://doi.org/10.1037/a0031034 (https://www.hsph.harvard.edu/tyler-vanderweele/tools-and-tutorials/)
SAS code: interaction, mediation, and four-way decomposition analyses	A Unification of Mediation and Interaction: A 4-Way Decomposition (VanderWeele et al.12)	https://doi.org/10.1097/EDE.0000000000000121