assignMarkerCombinations
                        Assing each cell to a combination of gated
                        markers.
calcPolyfunctionality   Calculate the frequency of polyfunctional cells
extractCellCounts       Get number of cells positive for each distinct
                        marker combination
getMarkerPositivity     Create dataframe of marker positivity
plotCellCountsAtLeast   Plot counts of cells expressing at least 1, 2,
                        ..., n markers.
plotCellCountsExactly   Plot counts of cells expressing exactly 1, 2,
                        ..., n markers.
plotMarkerComb2DScatters
                        Plot 2D scatterplots of all marker
                        combinations.
plotMarkerCombHeatmap   Plot a heatmap of all possible marker
                        combinations.
