Consistent with a negative regulatory role of p53 on CLP36 expression, overexpression of p53 in the p53 null sarcoma cells (i.e., Saos-2) significantly reduced the protein level of CLP36 (Figure 1I), although in this case, the mRNA level of CLP36 was increased in response to overexpression of p53 (Figure 1I), indicating that in these cells p53 overexpression-induced down-regulation of CLP36 expression is at the post-transcriptional rather than the transcriptional level. Here, TP53 is linked to sarcoma.