In the present study, both the mRNA and protein expression levels of ATF4, DDIT3 and IκBα were markedly increased after SNP treatment in mice, suggesting that the SNP may be involved in two immunomodulatory signalling pathways to inhibit HepG2 tumour progression: the TNF‐α/ATF4/DDIT3 and TNF‐α/IκBα/PPARγ signalling pathways. The gene discussed is ATF4; the disease is neoplasm.