In the context of lung cancer cells not responding to signals that regulate growth, the process that is not appropriately regulated in the cancerous cells is mitosis.
Mitosis is the process by which a cell divides to produce two daughter cells, and in cancer cells, this process can become unregulated, leading to uncontrolled cell growth and proliferation.
Meiosis relates to the production of gametes and is not directly relevant in terms of cancer cell proliferation. Transpiration refers to water movement in plants and is unrelated to cell division. Fertilization involves the union of gametes and is also not applicable to the context of cancer cell growth.