Kinomes have been annotated in all kingdoms of life, as protein phosphorylation lies at the heart of cell signaling. Receptor tyrosine kinases (RTKs) are key cell surface receptors that orchestrate a host of biological processes in multicellular organisms, from development to cancer. Approximately 10% of the human kinome encodes ‘pseudokinases’, a subgroup of protein kinases initially predicted to be incapable of catalytic activity, due to mutation in the canonical motifs defining enzymatically active kinases. Although a loss of catalytic activity appears to be a feature of many pseudokinases, the ability to bind to and/or hydrolyze ATP (sometimes very weakly) can be detected in a number of cases. Pseudokinases are thought to fulfil one, or more, of four distinct cellular functions, namely signaling modulator, anchor, competitor and integrator. However, for most pseudokinases, there is a chronic lack of small molecule probe compounds, cell permeable inhibitors or activators or other basic reagents such as validated antibodies. This means that, despite the large amount of evidence available in databases suggesting that pseudokinases are important in disease (and indeed, 2/3 of pseudokinases are dysregulated in diseases) their biological analysis has somewhat been neglected, especially when compared with their active counterparts.