The paper entitled “Convenience versus Biological Significance: Are PMA-Differentiated THP-1 Cells a Reliable Substitute for Blood-Derived Macrophages When Studying in Vitro Polarization?“ showed some fascinating results. Researchers usually use human monocyte-derived macrophages (MDMs) to generate macrophages for their studies. However, these macrophages have short life spans, and they are variable between individuals, so in this study, they looked at another cell line called phorbol-12-myristate-13-acetate (PMA)- differentiated THP-1 cells to see if they can use these cells that are more convenient to use in studies instead of DMDs.

Strengths:

1. In the abstract, the research question was clearly stated, and they gave a nice outline of the methods they used to conduct this study.

2. This paper is exciting because there have been no studies done in which the researchers have polarized the macrophages that they got from both cell lines and want to investigate if they have the same features.

3. The methods section is mentioned very clearly, and the authors have provided enough information to replicate the study.

Comments:

1. I think instead of writing the title as a question, they should have just mentioned the result that they got. This way, people can tell what the result of their experiments was without even reading the paper. The title would look better if written like the following, PMA-differentiated THP-1 cells are a good Substitute for blood-derived macrophages exclusively when studying macrophage polarization.

2. I do not think it’s necessary to write the entire forward and reverse primer sequences for the genes in Table 1. If people are interested in the primer sequences, they can search them online.

3. For the figure captions, whenever they used A and B, they put the alphabet after the sentence instead of before it, so it was confusing to figure out which alphabet is showing which part of the figure. I think it would be easier to read the caption if they had written the alphabet first and then talked about the figure.

4. In figure 2, I think it would have been better if they had used less bright colours and more mellow colours.

5. In figure 4, it is not easy to interpret the data from the two graphs above the bar graphs. There are no axes drawn, and if someone has no experience with using beads, they will not be able to tell what the authors are trying to show from those two figures. Also, I think it would be better to use mean±standard deviation to see the variability of the results obtained each time. Using SEM just shows the accuracy of the mean that was obtained. In addition, I would like to know why the authors did three experiments with THP-1 and 7 with MDM? I think it would have been better to perform the same number of experiments for both cell lines.