We study the relations between boundaries for algebras of
holomorphic functions on Banach spaces and complex convexity of
their balls. In addition, we show that the Shilov boundary for
algebras of holomorphic functions on an order continuous sequence
space $X$ is the unit sphere $S_X$ if $X$ is locally c-convex. In
particular, it is shown that the unit sphere of the Orlicz-Lorentz
sequence space $\lambda_{\varphi, w}$ is the Shilov boundary for
algebras of holomorphic functions on $\lambda_{\varphi, w}$ if
$\varphi$ satisfies the $\delta_2$-condition.