Some KI67− cells with stem cell properties were observed [S4+/K−] thus indicating their quiescent/non-proliferating state of cell cycle/dormancy [S4+(c) /K+(c), S4+(c) /K+(n)].KI67(c) cells are typically observed in cancer tissue and by virtue of expression of OCT4+ [O+(n)/K+(n), O+(n)/K+(c)] and SSEA-4+ [S4+/K+(c)] stem cell properties signify a proliferating population of stem cells with probable tumorigenic potential. This evidence concerns the gene POU5F1 and cancer.