The present invention provides methods of treatment using inhibitors of DEK protein and DEK activity. Such methods include, but are not limited to, methods of preventing, treating, and / or ameliorating inflammatory diseases, infections, autoimmune diseases, malignant diseases, and other diseases or conditions in which DEK has been implicated. Such inhibitors of DEK protein include, but are not limited to, pharmaceutical compositions including single stranded DNA or RNA aptamers capable of binding to DEK. In some embodiments, such aptamers are useful for diagnosing DEK related diseases or conditions. Related kits and compositions are further provided.