The Conserved Domain-Search tool (NCBI) identified several conserved domains in the pc1 sequence of MSpV21, including ovarian tumor-like cysteine protease (OTU), N-terminus bunyavirus endonuclease (Endo), domain of unknown function found in viruses (DUF3770), and bunyavirus RNA-dependent RNA polymerase (RdRp) (Figure 1B). This evidence concerns the gene CTSB and ovarian neoplasm.