In 2000, Robert Weinberg and Douglas Hanahan proposed the 6 Hallmarks of Cancer, which are found in most if not all cancers. This article describes how 11 viruses and 8 bacteria may stimulate the development of the first hallmark, self-sufficiency in growth signals. For this, viruses and bacteria either stimulate the synthesis of growth factors in the cell, or activate growth factor receptors, or regulate the expression of a gene involved in the transduction of a signal of cell division initiation from growth factor receptor.