The Hubble Frontier Fields represent the opportunity to probe the high-redshift evolution of the main sequence of star-forming galaxies to lower masses than possible in blank fields thanks to foreground lensing of massive galaxy clusters. We use the BEAGLE SED-fitting code to derive stellar masses,
and redshifts from
galaxies within the ASTRODEEP catalogue. We fit a fully Bayesian hierarchical
model of the main sequence over $1.25 3$, measurements of the main sequence to low masses and high redshifts still
strongly depend on priors employed in SED fitting (as well as other fitting
assumptions). Future data-sets with JWST should improve this.