Figure 6

Prediction of tissue malignancy by the ratio R = cytidine-5-monophosphate / pentadecanoic acid. (A) Up-regulation of cytidine-5-monophosphate in cancer compared to normal tissues. (B) Down-regulation of pentadecanoic acid in cancer compared to normal tissues. (C) Histogram showing the distribution of the ratio R in cancer and normal tissues (x-axis: log2 scale). R was significantly higher in cancer than in normal tissues (p = 8.3e-74, Welch’s t-test). A cut-off at R = 0.39 maximizes the sum of sensitivity and specificity. (D) ROC curve of R with confidence intervals for sensitivity (red lines) and specificity (green lines). The cut-off leads to at sensitivity of 94.8% and a specificity of 93.9% for the separation of cancer from normal tissues.