THIO kills cancer cells via dual mechanisms of action: (a) induction of DNA damage pathway results in the formation of Telomere Dysfunction Induced Foci (TIF), followed by rapid G2/M arrest or cell death of telomere-positive cancer cells; and (b) activation of cGAS-STING-dependent innate and adaptive immune responses upon release of damaged tumor DNA resulting from THIO treatment. This evidence concerns the gene CGAS and cancer.