You must think that I am pedantic and stubborn ... well, that's me ... I put the pieces together as you painstankingly taught me to do. You have already stressed that the following Fasta files contains EXPERIMENTALLY VALIDATED miRNAs. "ftp://ftp.sanger.ac.uk/pub/mirbase/sequences/CURRENT/mature.fa.gz" "ftp://ftp.sanger.ac.uk/pub/mirbase/sequences/CURRENT/maturestar.fa.gz " However, if I got it right, the Homo Sapiens PREDICTED miRNAs and genes dataset from Ensembl that looks like the following, contains associations (miRNA,gene) that for sure have been PREDICTED but not necessarily EXPERIMENTALLY VALIDATED. Am I right ? GROUP SEQ METHOD FEATURE CHR START END STRAND PHASE SCORE PVALUE_OG TRANSCRIPT_ID EXTERNAL_NAM 1 Similarity mmu-miR-707 miRanda miRNA_target 2 120824620 120824640 + . 15.3548 2.79654e-02 ENST00000295228 INHBB 2 Similarity hsa-miR-647 miRanda miRNA_target 2 120824263 120824281 + . 16.3205 3.70140e-06 ENST00000295228 INHBB Therefore my data blocks associate miRNAs with a number of genes 3'UTR regardless of their VALIDATION. Presumably just a subset of all predicted are actually VALIDATED. This is no time or energy wasted because this bulk miRNA --> genes 3'UTR data will be very useful for testing the program that is being developed. However, getting just the VALIDATED miRNA --> genes 3'UTR is step-1 to train the algorithm. A Bioinformatic guy, who is very good with Genetic and Evolutionary algorithms, is developing a program aimed at predicting miRNA targets. >From my understanding, these algorithms are similar to Neural Networks, thus they have to be trained first, then tested on a supervised set. If these two stages are performed correctly, the algorithm should then discriminate on the basis of rules learnt from the training. Bottomline, I guess I can't spare myself from dealing with miRecords XLS file as well .... Basically I should use the miRecords VALIDATED data to screen the information I am getting through the procedure your taught me. The downside of this further mapping is that miRecords apparently does not offer an ftp or any other automatic data transfer protocol. Kind regards, Maura tutti i telefonini TIM! [[alternative HTML version deleted]]