Evaluation of the efficacy of M4K compounds in DIPG patient-derived cell lines is essential before any promising compounds can be further tested in mouse xenograft models. This approach can aid in narrowing down clinical compound candidates and reduce the time, resources and animal sacrifice needed downstream. A robust and efficient readout for the changes in the viability of the DIPG cells needs to be established before it can be used to evaluate the M4K compounds. In addition, the amount of cells to be seeded at the beginning of the experiment has to be optimised to avoid overcrowding and starvation of the cells after extended culture times. Overcrowding and starvation will lead to increased cell death and prevent accurate estimation of the potency of M4K compounds (EC50).