The expression of evolutionarily novel genes in tumors was predicted by hypothesis of the possible evolutionary role of tumors (A.P. Kozlov, “Evolution by Tumor Neofunctionalization”, Elsevier/Academic Press, 2014). In my lab we described several genes with dual specificity - evolutionarily novel genes expressed specifically or predominantly in tumors (OTP, ESRG, PVT1, ELFN1-AS1, HHLA1, DCD, SPRR1A, CLLU1, PBOV1 and others). We also described the evolutionary novelty of the whole classes of genes expressed predominantly in tumors, ie, CT-X genes and genes of noncoding tumor specifically expressed RNAs. We studied the phylogenetic distribution of the orthologs of genes expressed in tumors and found that different functional gene classes have different evolutionary novelty. Some of them are enriched with evolutionarily novel genes. We showed that evolution of oncogenes, tumor suppressor genes and differentiation genes occurred in a parallel way, which supports the participation of tumors in the origin of new cell types. Some human genes which determine progressive traits originated in fishes and were first expressed in fish tumors. I also studied the literature data on the specificity of expression of evolutionarily novel genes originated through different molecular mechanisms. The existing data suggest that genes originated by gene duplication; from endogenous retroviruses; by exon shuffling; and de novo are expressed in tumors, sometimes with high tumor specificity. The conclusion is made that the expression of evolutionarily novel genes in tumors may be a novel biological phenomenon with important evolutionary role.