We note that some crispants had two legs instead of three, and one crispant had four legs, an example of the variable phenotypes that result from targeting tbx3a in sea robins which resembles both the increases and decreases in digit number previously reported in human patients with Ulnar-mammary syndrome.33 Comparison of genes upregulated in pectoral fins and leg 3 highlights the 45 genes driving tbx3a crispant leg 3 to become more similar to the pectoral fin, including several fin genes from zebrafish studies (csf1b, ntd5, grem1b, dlc1, and lamb2l) (Figure S5C;36). This evidence concerns the gene LAMB2P1 and ulnar-mammary syndrome.