FOLH1 and neoplasm: Once entering PSMA positive prostate cancer cells, the disulfide linker was cleaved by intracellular GSH and the probe was subsequently self‐assembled into nanoaggregates with 53.0% increase in r1 values due to lower tumbling rate (τR), providing enhanced MR signal for PSMA positive tumor (Figure 4B).[108] In addition, GSH‐responsive disulfide linker can switch contrasting enhancement from T2 to T1.