There are more than 30 million single-nucleotide polymorphisms that are like a finger print of genetic code in human genome(37). International Haplotype Mapping Project characterizes these SNPs in variety of population for public usage(38). Researchers can use these databases to identify association between disease risk .disease studies and genome- wide association studies linked by commercially available microarrays (SNP chips)(39). When specific allele of a SNP is present , a fluorescent signal is produced by using allele specific oligonucleotide probes for SNP arrays and array have skill of analyzing up to 1 million SNPs in a single sample(40). Also allelic imbalance, copy number variation, or loss of heterozygosity of cancer genome can be screened by SNP array.

Microarray analysis

Expression levels of thousand gene in cancer is analyzed with single experiment of microarray. Microarrays that are chips have immobilized capture molecules serve as probes to bind fluorescently labeled targets prepared from the two samples for comparing (41). These capture molecules can be oligonucleotides or cDNA. MRNA, miRNA, DNA and protein microarrays are most popular analysis. Gene expression profiling has been used for catogarizing unique subtypes of cancer, identifying invasive and non invasive cancer type’s phenotype, forecasting prognosis and response to treatment and risk of recurrence(42). New miRNA microarray platform data’s can be used as a cancer biomarker. To classify patients prognostic groups and treatment subgroups, miRNA signatures is used. Also misroarray is used to determine epigectic alteration that is contributed to tumorigenesis and direct to manage patient(43).

Proteomics by mass spectrometry

Changing of protein profiles in cancer cell is important to determine new biomarker and might help to classify of tumors subtypes(44). Proteomic analysis have more advantage than measurement of mRNA. Because protein is the final effector molecule and their level can not overlap the level of mRNA due to the posttranscriptional modifications(45). In addition to that , protein-protein interactions contribute to cellular pathways and carcinogenesis. Proteins are quanrified in mass spectrometry according to their mass to