Indeed, examples of tissue-specific genes that were downregulated in cell lines were identified for blood cells (Figure 4, cluster A, for example, PBXIP1, ISGF3 and IkB-alpha), brain tumors (Figure 4, cluster C and sample cluster 6, for example, CCND2 and APPBP2), renal biopsies (Figure 4, cluster E, for example, hMT-If) and brain normal and tumor biopsies (Figure 4, cluster F, for example, Protocadherin 2). Here, APPBP2 is linked to brain neoplasm.