The important characteristics of cancer cells are:
1. Immortilization: With proper nutrition cancer cells thrive for indefinite period of time.
2. Loss of contact inhibition: Characteristics of the membrane of cancer cells are changed so that the power of identification and communication are lost.
3. Adhesiveness: Neoplastic cells can adhere to any other cell types, but the normal cells cannot.
4. Invasiveness: Due to the changed characteristics of plasma membrane or increased secretion of proteases, cancer cells can attack any organ and can enter its tissues.