To follow the rearrangement of the receptor upon contact with a target cell, we co-cultured Jurkat T cells co-expressing GFP-tagged HER2-CAR and the membrane marker SNAP-CAAX with HER2+ SK-BR-3 cancer cells which exhibit elevated HER2 receptor levels on their cell surface (Dai et al., 2017) (Fig. 2A, Supplementary video 1). Here, ERBB2 is linked to cancer.