NGFR and pheochromocytoma: To determine if A1EVs can affect neuron differentiation or drive neurite growth, 1 × 108 A1EVs were added to cultured PC-12 cells, a rat pheochromocytoma line of the adrenal medulla that expresses the nerve growth factor (NGF) receptor and respond to NGF by generating plasma membrane projections that share similarities to neurites.