You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Chemical"].

Please return the output as a JSON object of the format: {"Chemical": ["Arsenic", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Kinase CK2 inhibition: an update. Protein kinase CK2 (Casein Kinase 2) is an essential, ubiquitous and highly pleiotropic protein kinase, implicated in several human diseases. In the last decade, several inhibitors of CK2, have been discovered and characterized to be ATP-competitive compounds. However, only one of them, CX-4945, has recently completed Phase I clinical trial as potential anticancer drug. In this review, we report all chemical classes of CK2 inhibitors available in literature, focusing our attention on conventional ATP-competitive and on non ATP-competitive inhibitors, which could represent a new frontier in CK2 inhibition and, consequently, a promising field of study in discovering new drug candidates.
{"Chemical": ["ATP", "CX-4945"]}