Searching for FLASH domains

It is possible to raise doubts about research indicating that a protein named FLASH, required during programmed apoptosis to regulate the proteolytic cascade that leads to the death of the cell, is a functional analogue of mammalian Apaf-1 and its nematode homologue CED-4. Subsequent research was not able to identify any sequence similarity between FLASH and the Apaf-1/CED-4 or death-effector domain domains. Those responsible for the original research defend their work, but acknowledge that they may have overestimated the structural homology of FLASH with CED-4, even though these proteins are functionally homologous.