In tumor research, the occurrence and origin of tumors are the fundamental problems. In the 1970s, the basic discussion of the developmental biology problem of tumors was proposed, and it was believed that tumorigenesis is closely related to developmental biology. Tumors are abnormal biological structures in organisms, and their biological behavior is very similar to that of the early embryo. Many tumor-related genes also serve regulatory roles in the normal development and differentiation of embryos. However, it remains unclear whether gene expression in early embryos has any similarities with tumor cells. In this study, to compare the similarities and differences in gene expression between early embryos and tumor cells, reverse transcription-quantitative PCR was conducted to determine and compare the relative expression levels of nine tumor-related genes in the brain glioma cell line, T98G, and in the early embryo of Spodoptera litura, which is fast-growing, low-cost, easily accessible and easy to observe. The expression of tumor-related genes in early embryos and the similarity of regulatory mechanisms between early embryonic development and tumor growth were explored. In conclusion, tumor growth may be regarded as an abnormal embryogenic activation that happens in the organs of adult individuals.