They also found that cognitive impairment severity and difficulty in performing daily activities were correlated with levels of urinary exosome Ser(P)‐1292 LRRK2.6 Studies have shown that exosomes are involved in the transmission and release of α‐synuclein, which is closely related to PD pathogenesis and dysfunction, and is the main component of Lewy bodies.7, 8 Given the difficulty in obtaining brain tissue and the properties of exosomes, it is appropriate to use exosomes rather than brain tissue to study PD. Here, LRRK2 is linked to Parkinson disease.