ZFP36L1 and arthritic joint disease: However, deleting Zfp36l1 and Zfp36l2 in addition to Zfp36 in myeloid cells led to the development of early lethality, accompanied by severe inflammatory arthritis and bone degradation, suggesting that all three TTP family members acted synergistically in the regulation of pro-inflammatory regulators of arthritis and the other aspects of this complex inflammatory syndrome.