CDKN2B and Miyoshi myopathy: However, one WT cell line showed loss of Trp53 and p53 and retention of both Cdkn2a and Cdkn2b. Most of MM cells from Htz Arf mice showed hemizygous loss of Faf1 and down-regulation of its protein, which regulated TNF-α-mediated NF-κB signalling pathway in these cells.