Also, it is well known that the outcome ofPPARγ signalling is highly context specific, that is, diametrally oppositebiological effects can be seen in different situations [5, 6, 34, 36].Resolution of the different observations in NHU cell cultures in vitro and rat tissue in vivo is ofobvious relevance for elucidating the bladder carcinogenicity mechanisms ofdual-acting PPARα+γ agonists in rats, and elucidating the human relevance ofthe rat bladder cancer findings (Table 1). Here, PPARA is linked to urinary bladder cancer.