This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General pathology, Subject name: Pathology
The following is not a feature of malignant transformation by cultured cells- 
Select and explain. 
A. Increased cell density, B. Increased requirement for growth factors, C. Alterations of cytoskeletal structures, D. Loss of anchorage
B: Increased requirement for growth factors
Answer: B: Increased requirement for growth factors 
Explanation: Malignant transformation is the process by which cells acquire the propeies of cancer. This may occur as a primary process in normal tissue, or secondarily as malignant degeneration of a previously existing benign tumor. Causes of malignant transformation There are many causes of primary malignant transformation, or tumorigenesis. Most human cancers in the United States are caused by external factors, and these factors are largely avoidable.