Parkin is an E3 ligase in the ubiquitin-proteasome system . Many mutations in parkin have been associated with a familial form of Parkinson's disease termed autosomal recessive juvenile parkinsonism . How loss of function of parkin leads to dopaminergic cell death in this disease is unclear. The prevailing hypothesis is that parkin helps degrade one or more proteins toxic to dopaminergic neurons. Putative substrates of parkin include synphilin-1, CDCrel-1, and Pael-R.

A Parkin is also a moist and sticky ginger cake made in Northern England, primarily in Yorkshire.