Normal and SSc fibroblasts were transfected with control and PKC-δ specific siRNA or were cultured in media containing either a control peptide consisting of a dimer of the TAT protein transduction domain (PTD) [21] or with a PKC-δ specific inhibitory peptide that targets the N-terminal C2 domain fused to a single TAT PTD [22]. Here, PRKCD is linked to systemic sclerosis.