| All of the biomarkers and their information included in CBD are collected from PubMed database with the key words: (((((biomarker [Title/Abstract]) OR marker [Title/Abstract]) OR indicator [Title/Abstract]) OR predictor [Title/Abstract])) AND ((((((colorectal cancer [Title/Abstract]) OR rectal cancer [Title/Abstract]) OR bowel cancer [Title/Abstract])))). Figure 3 shows the procedure of data collection.
Figure 3. Data collection procedure
Total 1134 records included 870 different biomarkers from 1115 articles were collected in CBD, which were separated into four kinds according to the different biology source: Protein, RNA, DNA and Other Biomarker.
Figure 4 Biomarker category distribution inside CBD
Figure 5 Biomarker category distribution inside CBD (detailed)
383776 people were involved in CBD, of which 170694 were male and 144201 were female.(Figure 6)
Figure 6 Gender distribution inside CBD
CBD continues CRC biomarker researches from 451 different cities of 83 countries, which from 6 Continents: Africa, Asia, Europe, North America, Oceania, South America. Figure 7 shows the distribution of researches according to continents. Also we selected the top 100 cities with most number of researches to map on the Bing map, from which you can scan the CRC biomarker research situation in city level (Figure 8). Figure 9 presents the top 20 most number researches cities worldwide.
Figure 7 Research amount distribution according to continents
Figure 8 Top 100 cities with most number of researches. 
Figure 9 Top 20 cities with the most number of researches
Also, we separated the samples inside CBD into Asian and Non-Asian race to research the different and similar things in different races, and the result of which are presented in Figure 10. An interesting phenomenon is that research numbers for Asian race is more than Non-Asian race (a), but the amount of people the opposite (b). From figure 10c and 10d you can compare the different of most used biomarkers in Asian and Non-Asian race.
Figure 10 Research situation between Asian race and Non-Asian race
Meanwhile we calculated the cancer location of each concluded research, and the number of colon, rectum cancer are showed in figure 11, from which we can see that most of research (770) studied both colon and rectum.
Figure 11 Number about cancer location
Precisely, we summarized the research with sample mean age and accurate amount to calculate the final mean age of our all samples. And the result is presented in figure 12.
Figure 12 Proceduce for mean age calcultate
Meanwhile we also counted the relative cancer stage from these biomarker researches showed in Figure 13.
Figure 13 Summary of cancer stage for included researches
The source where the biomarkers come from were also calculated, showing in Figure 14a and from which we can see that most of the biomarkers are from tissue(66%), blood(17%) and cell line(13%). Also the result shows that people like to use molecular biology together with clinical experiment to study CRC biomarkers since the cell line is often been used together with blood and tissue(Figure 14b).
Figure 14 Summary of biomarker source
For the function of biomarkers in our database, we also made professional statistic by summarizing them into three types: Diagnostic biomarker, therapeutic biomarker, and prognostic biomarker. (Figure 15)
Figure 15 Biomarker application distribution
As we all know, experiment method is very important to a research, we also summarized the experiment used by each research. Figure 16 showed the experiment methods which were used more than 5 times. 
Figure 16 Experiment methods used more than 5 times
We also concluded the Journal where these CRC biomarker researches were published, and figure 17 shows the Journal with more than 10 related researches.
Figure 17 Journal whth more than 10 published papers
Finally we also concluded the first authors of included papers, and Figure 18 shows the summary of first author with most published researches.
 Figure 18 Summary of most published researches team
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