Taniguchi's work is mostly focused on immunity and oncogenesis, in particular on the mechanisms of signal transduction and gene expression.

While working at the Cancer Institute in Tokyo, he conducted breakthrough research on sequencing the cDNA, and identified two cytokine genes, interferon-beta and interleukin-2.

He then went to the University of Zurich, where in 1978 he received his doctorate in molecular biology under the supervision of Charles Weissmann.

He was selected as a Person of Cultural Merit by the Government of Japan and as an honorary doctor by the University of Zurich (2007).

He is a member of the National Academy of Sciences, USA (since 2003) and an honorary citizen of Aridagawa, Wakayama (since 2010).