Cool Stars Have Different Mix of Chemicals
From the NASA Spitzer news page, A look at the chemicals around smaller and cooler stars than the sun show that they do not have hydrogen cyanide, but acetylene. The speculation is that ultraviolet light is involved in the creation of HCN. Also small stars have extreme magnetic bursts that can be disruptive for life. So the implications for life on planets around these stars seems to be less likely than sun-like stars.
