KRAS and neoplasm: Theoretically, a number of these features are correlated with intra-tumor heterogeneity attributed to various factors including necrosis, hypoxia, angiogenesis, hemorrhage, even genetic variations [37–41] For example, Variance is negatively associated with angiogenesis in CRCs without KRAS mutant, while positive association has been demonstrated between Skewness and angiogenesis in CRCs with KRAS mutant [41].