In addition, the increased tumor formation observed in TCF7L1-induced mice was tightly tet-regulatable; when not fed doxycycline-containing chow, TCF7L1-inducible mice subjected to DMBA/TPA treatment were indistinguishable from their control littermates, developing tumors at a comparable rate (Figure 2—figure supplement 3; n = 17 TCF7L1-uninduced, n = 16 control). This evidence concerns the gene TCF7L1 and neoplasm.