Most of the mutations that contribute to cancer occur in somatic cells- but germ line mutations can also contribute egg ○ o sperm ○ zygote growth and germ line mitotic differentiation divisions 2 meiotic divisions mitotic divisions endoderm colon gametes(eggs or sperm)Most of the mutations that contribute to cancer occur in somatic cells – but germ line mutations can also contribute egg sper m zygot e endod e r m col o n g rowth an d di ff e rentiation mitotic di visions mitotic di visions 2 m eiotic di visions gam etes (eggs or spe r m) ger m line