To study the endosomal compartments, control and cystinosis ciPTEC cells and CTNS KD HK-2 cells were stained with antibodies specific to markers of early endosomes and late endosomes/lysosomes (EEA1 and LAMP1 respectively), the ER (VAP-A), Golgi (GM130) and TGN (TGN46). Here, VAPA is linked to cystinosis.