The high proportion of sequences with similar domains suggested the presence of homologous peptides. Therefore, we clustered mACPs into families guided by moderate-high sequence similarities (SOSA, Eq.5) and coincidental name tags (e.g., Temporin-PE). We catalogued 58 families (Table ), 22 of which presented at least two homologous sequences and the remaining 36 had each a single representative. Then, we reported the distributions of mACP families across the 11 cancer cell lines; 6 in Figure and 5 in Figure . We also indicated the differential enrichments in positively charged residues (Figures and), aliphatic and aromatic residues (Figures and) and small residues (Figure ). Most non-selective mACPs with higher levels of hydrophobic residues were conjointly tested against blood cancer cell lines Jurkat E6-1, K562, and breast cancer cell line MDA-MB-361 belong to the P18 and CRAMP-18 families. These peptides demonstrated anticancer activity within the same range (CRAMP-18: pIC50 ~ 4-4.5 and P18: pIC50 ~ 4-5.5). Members of the BP100 family were exclusively reported against blood cancer cell line K562. Likewise, HeLa S3, SW480, and CCRF-CEM were evaluated with a handful of selective mACPs from the HAL-1 and LL-III families and non-selective homologs derived from Macropin-1. These families presented moderated levels of charged, aliphatic and aromatic residues. Selective LL-III and non-selective Macropin-1 homologues exhibited potent anticancer activity with pIC50 values ranging between 4.8 and 5.6 against CCRF-CEM and HeLa S3, suggesting similar membrane lipid compositions of both blood cancer cell lines. The five other cancer cell lines (A549, HL-60, NCI-H157, PC-3, U251-MG), shown in Figure , were evaluated with an array of heterologous sequences apparent to 29 mACP families with 1-3 representatives. Among the 15 common mACPs exhibiting anticancer activity against U251-MG, NCI-H157, and PC-3 (Figure ), we identified the selective dermaseptins owning many small and aliphatic residues. Positively charged members of Buforin-2, MP-C, Temporin-PE, TsAP-1, and TsAP-2 families showed equipotent (pIC50 ~ 5-6) and non-selective anticancer activity against the three cell lines. Membranolytic TsAP-1 and TsAP-2 peptides bestowed high levels of hydrophobicity. Our Kolmogorov-Smirnov half-matrices revealed moderate fittings between cancer cell lines A549, HL-60 and PC-3, implying possible overlaps in positively charged mACPs (HL-60/A549: with a KS p-value of 0.765, Figure ) or small and aliphatic peptides (HL-60/PC-3: with a KS p-value of 0.799, Figure ). However, most peptides differed in nature and belonged to distinct mACP families, across all three cancer cell lines, with few exceptions, such as Buforin-2, Gaegurin 5 and PTP homologues (Figure ). Besides their heterology, many highly potent and nonselective mACPs against the three cancer cell lines shared similar characteristics; elevated levels of positively charged lysine, arginine, histidine (Figure ), and moderated-high hydrophobicity (Figure ). The most potent example is the KLW peptide with a pIC50 value over 6 when tested against lung cancer cell line A549. The five cancer cell lines U251-MG, NCI-H157, A549, HL-60 and PC-3 might present comparable levels of negatively charged lipids on their cell surfaces to accommodate these non-selective mACPs.