Since we found transient association between Mcl-1 and Mule in cancer cells, in addition to HRF and pERK1/2 we are examining deubiquitinating enzymes (DUBs) that function downstream in ubiquitin pathways and have the potential to be the final editors of protein ubiquitination status and thus determine substrate fate (Millard and Wood, 2006). Here, MCL1 is linked to cancer.