Examples of other post-translationally modified proteins that are biomarkers in plasma include the previously identified slightly truncated forms of SAA [29], ApoA-I, and ApoA-II [33], the glutathionylated and truncated forms of transthyretin in ovarian cancer [34] and in a rat model of glioma growth [35], and truncated forms of ITIH4 in ovarian cancer [34]. Here, APOA2 is linked to central nervous system cancer.