Although prevention should be our primer facing cancer, without proper understanding to the nature of cancer as a disease, we will be failing to meet our global aim of eradicating it. Cancer cell should be looked at as a dedifferentiated cell rather than an abnormally diving cell. And, cancer causation should be understood as a threshold phenomenon due to cumulative inactivation of tumour suppressor gene and/or activation of oncogenes - with exceptions. And that cancer eruption at a specific site in a tissue does reflect DNA mutations at that site but rather the weakest point in a decayed pipe and specific tissue expression of genes at that tissue. This is because the mutation most probably is affecting all of the body cells. For all of its activity, cancer cell uses nothing but our genetic makeup - albeit, in a dysegulated manner. In a very simplified approach, this book tried to present a straightforward picture to the problem; definition, causation and molecular changes - along with related hereditary predisposition, diagnosis and basic idea for the available treatment modalities. Once we understand the problem correctly, we will start realising that most of the in-clinic practices for cancer treatments are erroneous reflecting the never used "Cure" word. Cancer cell is a dedifferentiated cell that divides in an uncontrolled fashion but at a rate much slower than so many normal cells in the human body. Therefore, targeting cancer cell as a dividing cell led to the well-known side-effects of the so called cytotoxic treatments. Rather we need a redifferentiating approach to the cancer rather than killing the cancer cell.