I have some problems with ggplot legends, here is my first code with only the legend for corrGenes, which is fine.
gene1=c(1.041,0.699,0.602,0.602,2.585,0.60
Not sure if this is the best solution, but I was able to tell ggplot to have two scales, one for the colours (your points), the other one for the fill colour. Which fill colour you are probably asking? The one I added in the aes for the two lines:
plot = ggplot(data=DF,aes(x=gene1,y=BIME)) +
geom_point(size=5, aes(colour=corrGenes)) +
geom_abline(aes(fill="black"),intercept=0, slope=1) +
stat_smooth(aes(fill="blue"), method = "lm",se=FALSE) +
scale_fill_manual(name='My Lines', values=c("black", "blue"))+
ylab("BIME normalized counts (log10(RPKM))")+
xlab("gene1 normalized counts (log10(RPKM))")
