CSF1R and Hereditary diffuse leukoencephalopathy with axonal spheroids and pigmented glia: Given the dysregulated BBB phenotype in life and in post‐mortem ALSP samples and as CSF‐1R can differentially regulate endothelial–microglial crosstalk, we wanted to elucidate the impact of disrupted CSF‐1R signalling in brain endothelial cells.