Our previous study showed that prostaglandin J2 (PGJ2) interacting factor (PGJIF) was purified and identified with magnetic nanobeads. Farther analysis of PGJ2 function shows that PGJ2 inhibits cell proliferation and rhodamine 123 incorporation. Using PGJ2- immobilized nanobeads, two target proteins were also purified and identified as PGJIF1 and PGJIF2. PGJIF1 genetic analysis showed that PGJIF1 regulates cell proliferation as well as rhodamine 123 incorporation in mitochondria, indicating that PGJIF1 is one of the PGJ2 target proteins. The other target protein, PGJIF2, changes its intracellular localization in PGJ2-dependent manner. Using nanobeads technology, two PGJ2 target factors were purified and identified.