“…In all cases, a key challenge is the selection of features from each platform as inputs to the clustering algorithms; for example, it is possible to summarize mutations, gene expression, and DNA methylation events as binary alterations [80], and then treat any missing data as a non-alteration event. We anticipate that recent advances in methods for learning low-dimensional representations of multiple data types such as deep neural nets [83] will soon be applied in molecular classification of tumors, given the amount of molecular cancer data being produced and the successful application of deep neural nets in areas of computer vision, natural language processing, and biology [84]. Initial molecular subtype studies have often focused on clustering samples into subtypes based on gene expression in a single cancer type, which have provided robust biomarkers and subgroups, coherent with patient survival profiles (e.g, in breast cancer [85] or colorectal cancer (CRC) [86]).…”