Fig. 1

Illustration of LncRIndiv method and work-flow of this study. a Definition of stable and reversal lncRNA pairs. The red and blue circles represent lncRNA-A and lncRNA-B, respectively. The lncRNA-A and lncRNA-B are ranked according to the expression values, where the smallest expression value corresponds to the minimum rank and the greatest expression value corresponds to the maximum rank. Letters of a and c represent the number of samples with the expression level of lncRNA-A < lncRNA-B in normal and cancer samples, while b and d represent the number of samples with the expression level of lncRNA-A > lncRNA-B in normal and cancer samples, respectively. If lncRNA-A < lncRNA-B appears in more than 95% (a/(a + b) > 95%) of normal samples, lncRNA-A < lncRNA-B is selected as a stable pair. The Fisher’s exact test is used to test whether the rank of lncRNA-A < lncRNA-B is significantly reversed as lncRNA-A > lncRNA-B in cancer samples. The P values are corrected by Benjamini-Hochberg multiple tests and lncRNA-A > lncRNA-B with FDR < 0.1 is defined as a reversal pair. b The schematic diagram of LncRIndiv method. Take lncRNA-A as an example to describe the LncRIndiv method. Circles with different color represent different lncRNAs. The blue and purple human shapes represent the samples with or without reversal lncRNA pairs in each line, respectively. The red and green human shapes represent the samples are determined as with and without differential expression of lncRNA-A by the LncRIndiv method. See the detailed explanation of LncRIndiv in Method section. c The work-flow of this study