Seven days post infection (DPI 7) cell culture medium (supernatant, S) contained a major amount of mature v-BMP7, v-BMP2, and v-Noggin as revealed by immunoblots using an anti-2A antibody selective for 18 amino acids of 2A-peptides that remained at the C-terminus of v-BMP2, v-BMP7 and v-Noggin after successful ribosomal skipping (Figure 1B). Here, NOG is linked to infection.