In addition, optimal completeness of cytoreduction (CCR) is not strictly defined; traditionally, this is given a score and defined as a CCR0 (all visible disease removed), CCR1 (residual tumor nodules 2.5 mm or less), CCR2 (residual tumor nodules 2.5 to 25 mm), and CCR3 (residual tumor nodules > 25 mm), although some studies have opted to regard a complete resection as tumor less than 10 or 25 mm in size [44]. The gene discussed is CCR2; the disease is neoplasm.