This protocol is not finished, the dilution of 1:100 is not strong enough for human tissue. I used a normal TMA human tissue block plus a couple large tonsil & spleen slides. It could be that the primary antibody was not on long enough, or maybe the room temp should have been at 60C to help it sink in? The HIER method tris/edta 9.0 was found to work better than citrate 6.0 but I did not try a neutral pH solution.
If I were to try this again, I would go for stronger primary concentrations like 1:50 & 1:25 and make sure to use heat on both primary and secondary antibodies. According to the human protein atlas the c-maf antibody has many positive tissues of normal and abnormal tissues so if you have an all encompassing human TMA block or slides, I would use those first.