 # VAF - variant allele frequency

Variant allele fraction or frequency (VAF): the fraction of mutated reads for a given variant, which is a readout for the proportion of DNA mutated in the sequenced tissue.

# CCF - cancer cell fraction

Cancer cell fraction (CCF): the fraction of cancer cells from the sequenced sample carrying a set of SNVs.

$$CCF = VAF *\frac{1}{p}[pCN_t + CN_n(1-p)]$$

VAF: corresponds to the variant allele frequency at the mutated base

p: the tumor purity肿瘤纯度

CNt: the tumor locus specific copy number所在位置的拷贝数

CNn: the normal locus specific copy number (CNn was assumed to be 2 for autosomal chromosomes)正常样本的拷贝数

# 三种时间依赖的ROC t: 目标时间，t* 固定的随访时间，c 阈值，A-F为研究中的个体病例，其中ABC的指标高于c，DEF个体的指标小于c，实心圆表示发生事件的个体，空心圆表示Censored个体。

## Cumulative sensitivity and dynamic specificity (C/D)

$$\begin{array}{l} S{e}^C\left( c, t\right)= P\left({X}_i> c\Big|{T}_i\le t\right)\\ {} S{p}^D\left( c, t\right)= P\left({X}_i\le c\Big|{T}_i> t\right)\\ {} AU{C}^{C, D}(t)= P\left({X}_i>{X}_j\Big|{T}_i\le t,{T}_j> t\right), i\ne j.\end{array}$$

cumulative/dynamic(C/D)中cumulative是指Cumulative sensitivity，dynamic是指dynamic specificity。C/D是用的最广泛的ROC模型。 