Jon P Miller, Wesley W Zmolek: Process for treating proliferative skin diseases using certain 6,8-substituted ribofuranosylpurine-3,5-cyclic phosphates. SRI International, Thomas E Ciotti, January 18, 1983: US04369181 (22 worldwide citation)

Proliferative skin diseases such as psoriasis are treated by topically administering cAMP analogs of the following formula to the afflicted skin site at a dose that preferentially and significantly activates type II protein kinase: ##STR1## where: R.sub.6 is: