Here, we present a novel XAI method for GNNs where prediction instances are explained using Myerson values. We have developed an open source Python package to calculate Myerson values (for arbitrary games and as explanations for GNNs), available at . We investigated the interpretability of Myerson explanations on various chemical datasets, showing that Myerson explanations in combination with heatmaps can provide meaningful insight into the decisions made by the GNN. The results of this investigation are available at .