The second important consequence of the post-transcriptional control of s1pr1 by miR-19a is that since this microRNA is regulated by Tbx5 in zebrafish embryos (Chiavacci et al., 2015) then s1pr1 is indirectly under the Tbx5 control and may contribute to the zebrafish HOS phenotype caused by Tbx5 depletion. This evidence concerns the gene S1PR1 and Holt-Oram syndrome.