HTRA1 and ovarian cancer: Intriguingly, anoikis resistance in ovarian cancer has been previously linked with downregulation of another serine protease, HtrA1 [49]; however, this enzyme appears unlikely to be a direct target of SPINK1 since its primary substrate specificity directs cleavage following small hydrophobic or polar residues [50], but not after Lys or Arg as is typical of protease targets of SPINK1.