Cancer is caused by alterations in the cellular genome including single-nucleotide variations, small insertions and deletions (indels), copy number changes and other structural variations and, as such, their detection in a comprehensive manner is of critical importance for fully understanding cancer pathogenesis, improvement of diagnosis as well as the development of novel therapeutics. In this point of views, the recent development of massively parallel (or 'next-generation') sequencing technologies has provided an unprecedented possibility to accomplish this need by enabling single-nucleotide resolution analysis of the entire genome of cancer cells as well as more targeted analysis of coding sequencing or transcriptomes. Through international co-operations, a wide variety of cancer cell types have now been analyzed using these technologies to help unmask their pathogenesis. In this review, we briefly overview the recent advances in cancer research obtained through the massive effort of sequencing cancer genomes.