PGR and cancer: Notably, YAP1 point/small mutations have not been described so far and the reported 11q22 amplification events include multiple flanking genes in addition to YAP1. Some of these genes have been involved in cancer development, including a cluster of matrix metalloproteinase (MMP) genes [30], two members of the BIRC family of caspase inhibitors (BIRC2 and BIRC3) [31] and the progesterone receptor (PGR) [32].